641557405464 has 64 divisors (see below), whose sum is σ = 1631894592000. Its totient is φ = 210144654720.

The previous prime is 641557405441. The next prime is 641557405507. The reversal of 641557405464 is 464504755146.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 401779 + ... + 1201890.

It is an arithmetic number, because the mean of its divisors is an integer number (25498353000).

Almost surely, 2^641557405464 is an apocalyptic number.

It is an amenable number.

641557405464 is an abundant number, since it is smaller than the sum of its proper divisors (990337186536).

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

641557405464 is a wasteful number, since it uses less digits than its factorization.

641557405464 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1603968 (or 1603964 counting only the distinct ones).

The product of its (nonzero) digits is 8064000, while the sum is 51.

The spelling of 641557405464 in words is "six hundred forty-one billion, five hundred fifty-seven million, four hundred five thousand, four hundred sixty-four".