645271407 has 64 divisors (see below), whose sum is σ = 1124928000. Its totient is φ = 361324800.

The previous prime is 645271357. The next prime is 645271409. The reversal of 645271407 is 704172546.

645271407 is a `hidden beast` number, since 645 + 2 + 7 + 1 + 4 + 0 + 7 = 666.

It is not a de Polignac number, because 645271407 - 2¹⁵ = 645238639 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645271409) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 229969 + ... + 232757.

It is an arithmetic number, because the mean of its divisors is an integer number (17577000).

Almost surely, 2^645271407 is an apocalyptic number.

645271407 is a deficient number, since it is larger than the sum of its proper divisors (479656593).

645271407 is a wasteful number, since it uses less digits than its factorization.

645271407 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2869 (or 2863 counting only the distinct ones).

The product of its (nonzero) digits is 47040, while the sum is 36.

The square root of 645271407 is about 25402.1929565146. The cubic root of 645271407 is about 864.1334308780.

The spelling of 645271407 in words is "six hundred forty-five million, two hundred seventy-one thousand, four hundred seven".