121557434563773 has 12 divisors (see below), whose sum is σ = 189089342654940. Its totient is φ = 74804575116096.

The previous prime is 121557434563771. The next prime is 121557434563783. The reversal of 121557434563773 is 377365434755121.

121557434563773 is a `hidden beast` number, since 1 + 2 + 1 + 5 + 57 + 434 + 56 + 37 + 73 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 55813181355684 + 65744253208089 = 7470822^2 + 8108283^2 .

It is not a de Polignac number, because 121557434563773 - 2¹ = 121557434563771 is a prime.

It is a Smith number, since the sum of its digits (63) coincides with the sum of the digits of its prime factors.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 121557434563773.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121557434563771) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 519476215968 + ... + 519476216201.

It is an arithmetic number, because the mean of its divisors is an integer number (15757445221245).

Almost surely, 2^{121557434563773} is an apocalyptic number.

121557434563773 is a gapful number since it is divisible by the number (13) formed by its first and last digit.

It is an amenable number.

121557434563773 is a deficient number, since it is larger than the sum of its proper divisors (67531908091167).

121557434563773 is a wasteful number, since it uses less digits than its factorization.

121557434563773 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1038952432188 (or 1038952432185 counting only the distinct ones).

The product of its digits is 222264000, while the sum is 63.

The spelling of 121557434563773 in words is "one hundred twenty-one trillion, five hundred fifty-seven billion, four hundred thirty-four million, five hundred sixty-three thousand, seven hundred seventy-three".