645774520 has 16 divisors (see below), whose sum is σ = 1452992760. Its totient is φ = 258309792.

The previous prime is 645774517. The next prime is 645774539. The reversal of 645774520 is 25477546.

It is a Harshad number since it is a multiple of its sum of digits (40), and also a Moran number because the ratio is a prime number: 16144363 = 645774520 / (6 + 4 + 5 + 7 + 7 + 4 + 5 + 2 + 0).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8072142 + ... + 8072221.

Almost surely, 2^645774520 is an apocalyptic number.

It is an amenable number.

645774520 is an abundant number, since it is smaller than the sum of its proper divisors (807218240).

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

645774520 is a wasteful number, since it uses less digits than its factorization.

645774520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16144374 (or 16144370 counting only the distinct ones).

The product of its (nonzero) digits is 235200, while the sum is 40.

The square root of 645774520 is about 25412.0939711784. The cubic root of 645774520 is about 864.3579585289.

The spelling of 645774520 in words is "six hundred forty-five million, seven hundred seventy-four thousand, five hundred twenty".