64520781003725 has 12 divisors (see below), whose sum is σ = 80144426640084. Its totient is φ = 51527167902720.

The previous prime is 64520781003703. The next prime is 64520781003727. The reversal of 64520781003725 is 52730018702546.

It can be written as a sum of positive squares in 6 ways, for example, as 13129273952356 + 51391507051369 = 3623434^2 + 7168787^2 .

It is not a de Polignac number, because 64520781003725 - 2²⁴ = 64520764226509 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64520781003727) 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, 2236407794 + ... + 2236436643.

It is an arithmetic number, because the mean of its divisors is an integer number (6678702220007).

Almost surely, 2^{64520781003725} is an apocalyptic number.

It is an amenable number.

64520781003725 is a deficient number, since it is larger than the sum of its proper divisors (15623645636359).

64520781003725 is a wasteful number, since it uses less digits than its factorization.

64520781003725 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4472845024 (or 4472845019 counting only the distinct ones).

The product of its (nonzero) digits is 2822400, while the sum is 50.

The spelling of 64520781003725 in words is "sixty-four trillion, five hundred twenty billion, seven hundred eighty-one million, three thousand, seven hundred twenty-five".