645133060521 has 12 divisors (see below), whose sum is σ = 932138662000. Its totient is φ = 429959570040.

The previous prime is 645133060519. The next prime is 645133060543. The reversal of 645133060521 is 125060331546.

645133060521 is a `hidden beast` number, since 6 + 4 + 5 + 13 + 30 + 605 + 2 + 1 = 666.

645133060521 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 645133060521 - 2¹ = 645133060519 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (645133060511) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 10729771 + ... + 10789728.

Almost surely, 2^645133060521 is an apocalyptic number.

It is an amenable number.

645133060521 is a deficient number, since it is larger than the sum of its proper divisors (287005601479).

645133060521 is a wasteful number, since it uses less digits than its factorization.

645133060521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21522836 (or 21522833 counting only the distinct ones).

The product of its (nonzero) digits is 64800, while the sum is 36.

The spelling of 645133060521 in words is "six hundred forty-five billion, one hundred thirty-three million, sixty thousand, five hundred twenty-one".