121309856550 has 60 divisors (see below), whose sum is σ = 337061694156. Its totient is φ = 32349294000.

The previous prime is 121309856533. The next prime is 121309856579. The reversal of 121309856550 is 55658903121.

121309856550 is a `hidden beast` number, since 1 + 2 + 1 + 3 + 0 + 98 + 5 + 6 + 550 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 121309856496 and 121309856505.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 29 ways as a sum of consecutive naturals, for example, 14972476 + ... + 14980575.

Almost surely, 2^121309856550 is an apocalyptic number.

121309856550 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

121309856550 is an abundant number, since it is smaller than the sum of its proper divisors (215751837606).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

121309856550 is a wasteful number, since it uses less digits than its factorization.

121309856550 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29953075 (or 29953061 counting only the distinct ones).

The product of its (nonzero) digits is 324000, while the sum is 45.

The spelling of 121309856550 in words is "one hundred twenty-one billion, three hundred nine million, eight hundred fifty-six thousand, five hundred fifty".