521662640 has 40 divisors (see below), whose sum is σ = 1213902960. Its totient is φ = 208486656.

The previous prime is 521662633. The next prime is 521662649. The reversal of 521662640 is 46266125.

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

It is a junction number, because it is equal to n+sod(n) for n = 521662597 and 521662606.

It is not an unprimeable number, because it can be changed into a prime (521662649) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 131567 + ... + 135473.

It is an arithmetic number, because the mean of its divisors is an integer number (30347574).

Almost surely, 2^521662640 is an apocalyptic number.

It is an amenable number.

521662640 is an abundant number, since it is smaller than the sum of its proper divisors (692240320).

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

521662640 is a wasteful number, since it uses less digits than its factorization.

521662640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5589 (or 5583 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 32.

The square root of 521662640 is about 22839.9352013091. The cubic root of 521662640 is about 805.0012936723.

The spelling of 521662640 in words is "five hundred twenty-one million, six hundred sixty-two thousand, six hundred forty".