645263406 has 24 divisors (see below), whose sum is σ = 1406981784. Its totient is φ = 213716880.

The previous prime is 645263383. The next prime is 645263417. The reversal of 645263406 is 604362546.

645263406 is a `hidden beast` number, since 645 + 2 + 6 + 3 + 4 + 0 + 6 = 666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 111340 + ... + 116991.

It is an arithmetic number, because the mean of its divisors is an integer number (58624241).

Almost surely, 2^645263406 is an apocalyptic number.

645263406 is an abundant number, since it is smaller than the sum of its proper divisors (761718378).

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

645263406 is a wasteful number, since it uses less digits than its factorization.

645263406 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 228496 (or 228493 counting only the distinct ones).

The product of its (nonzero) digits is 103680, while the sum is 36.

The square root of 645263406 is about 25402.0354696233. The cubic root of 645263406 is about 864.1298592749.

The spelling of 645263406 in words is "six hundred forty-five million, two hundred sixty-three thousand, four hundred six".