645171507 has 8 divisors (see below), whose sum is σ = 955809680. Its totient is φ = 430114320.

The previous prime is 645171487. The next prime is 645171529. The reversal of 645171507 is 705171546.

645171507 is a `hidden beast` number, since 645 + 1 + 7 + 1 + 5 + 0 + 7 = 666.

It is not a de Polignac number, because 645171507 - 2⁷ = 645171379 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (645171577) 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, 11947594 + ... + 11947647.

It is an arithmetic number, because the mean of its divisors is an integer number (119476210).

Almost surely, 2^645171507 is an apocalyptic number.

645171507 is a deficient number, since it is larger than the sum of its proper divisors (310638173).

645171507 is a wasteful number, since it uses less digits than its factorization.

645171507 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23895250 (or 23895244 counting only the distinct ones).

The product of its (nonzero) digits is 29400, while the sum is 36.

The square root of 645171507 is about 25400.2265147380. The cubic root of 645171507 is about 864.0888339409.

The spelling of 645171507 in words is "six hundred forty-five million, one hundred seventy-one thousand, five hundred seven".