1221015433545 has 32 divisors (see below), whose sum is σ = 2172086841600. Its totient is φ = 650790410112.

The previous prime is 1221015433523. The next prime is 1221015433549. The reversal of 1221015433545 is 5453345101221.

1221015433545 is a `hidden beast` number, since 1 + 2 + 2 + 101 + 5 + 4 + 3 + 3 + 545 = 666.

It is not a de Polignac number, because 1221015433545 - 2²¹ = 1221013336393 is a prime.

It is a super-2 number, since 2×1221015433545² (a number of 25 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1221015433549) by changing a digit.

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 31 ways as a sum of consecutive naturals, for example, 2690292 + ... + 3111221.

It is an arithmetic number, because the mean of its divisors is an integer number (67877713800).

Almost surely, 2^{1221015433545} is an apocalyptic number.

1221015433545 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1221015433545 is a deficient number, since it is larger than the sum of its proper divisors (951071408055).

1221015433545 is a wasteful number, since it uses less digits than its factorization.

1221015433545 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5803086 (or 5803080 counting only the distinct ones).

The product of its (nonzero) digits is 72000, while the sum is 36.

The spelling of 1221015433545 in words is "one trillion, two hundred twenty-one billion, fifteen million, four hundred thirty-three thousand, five hundred forty-five".