521642403616 has 24 divisors (see below), whose sum is σ = 1027022506524. Its totient is φ = 260811290880.

The previous prime is 521642403577. The next prime is 521642403619. The reversal of 521642403616 is 616304246125.

It can be written as a sum of positive squares in 2 ways, for example, as 454281392016 + 67361011600 = 674004^2 + 259540^2 .

It is a super-2 number, since 2×521642403616² (a number of 24 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (521642403619) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 585366 + ... + 1177258.

Almost surely, 2^521642403616 is an apocalyptic number.

It is an amenable number.

521642403616 is a deficient number, since it is larger than the sum of its proper divisors (505380102908).

521642403616 is a wasteful number, since it uses less digits than its factorization.

521642403616 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 619444 (or 619436 counting only the distinct ones).

The product of its (nonzero) digits is 207360, while the sum is 40.

The spelling of 521642403616 in words is "five hundred twenty-one billion, six hundred forty-two million, four hundred three thousand, six hundred sixteen".