64131277520 has 40 divisors (see below), whose sum is σ = 149205367656. Its totient is φ = 25635281408.

The previous prime is 64131277487. The next prime is 64131277531. The reversal of 64131277520 is 2577213146.

64131277520 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 21393157696 + 42738119824 = 146264^2 + 206732^2 .

It is a tau number, because it is divible by the number of its divisors (40).

It is a super-2 number, since 2×64131277520² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 149027 + ... + 387906.

Almost surely, 2^64131277520 is an apocalyptic number.

It is an amenable number.

64131277520 is an abundant number, since it is smaller than the sum of its proper divisors (85074090136).

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

64131277520 is a wasteful number, since it uses less digits than its factorization.

64131277520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 538439 (or 538433 counting only the distinct ones).

The product of its (nonzero) digits is 70560, while the sum is 38.

The spelling of 64131277520 in words is "sixty-four billion, one hundred thirty-one million, two hundred seventy-seven thousand, five hundred twenty".