521985644 has 12 divisors (see below), whose sum is σ = 953191344. Its totient is φ = 249645264.

The previous prime is 521985599. The next prime is 521985647. The reversal of 521985644 is 446589125.

It is a junction number, because it is equal to n+sod(n) for n = 521985595 and 521985604.

It is not an unprimeable number, because it can be changed into a prime (521985647) 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, 2836787 + ... + 2836970.

It is an arithmetic number, because the mean of its divisors is an integer number (79432612).

Almost surely, 2^521985644 is an apocalyptic number.

It is an amenable number.

521985644 is a deficient number, since it is larger than the sum of its proper divisors (431205700).

521985644 is a wasteful number, since it uses less digits than its factorization.

521985644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5673784 (or 5673782 counting only the distinct ones).

The product of its digits is 345600, while the sum is 44.

The square root of 521985644 is about 22847.0051429066. The cubic root of 521985644 is about 805.1674067692.

The spelling of 521985644 in words is "five hundred twenty-one million, nine hundred eighty-five thousand, six hundred forty-four".