121577520645 has 112 divisors (see below), whose sum is σ = 251046535680. Its totient is φ = 55342973952.

The previous prime is 121577520641. The next prime is 121577520653. The reversal of 121577520645 is 546025775121.

121577520645 is a `hidden beast` number, since 1 + 2 + 15 + 77 + 520 + 6 + 45 = 666.

It is not a de Polignac number, because 121577520645 - 2² = 121577520641 is a prime.

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

It is a self number, because there is not a number n which added to its sum of digits gives 121577520645.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121577520641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 111 ways as a sum of consecutive naturals, for example, 6088117 + ... + 6108053.

Almost surely, 2^121577520645 is an apocalyptic number.

121577520645 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

121577520645 is an abundant number, since it is smaller than the sum of its proper divisors (129469015035).

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

121577520645 is an equidigital number, since it uses as much as digits as its factorization.

121577520645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20206 (or 20191 counting only the distinct ones).

The product of its (nonzero) digits is 588000, while the sum is 45.

The spelling of 121577520645 in words is "one hundred twenty-one billion, five hundred seventy-seven million, five hundred twenty thousand, six hundred forty-five".