645124651 has 6 divisors (see below), whose sum is σ = 679195140. Its totient is φ = 611065836.

The previous prime is 645124621. The next prime is 645124661. The reversal of 645124651 is 156421546.

It is not a de Polignac number, because 645124651 - 2¹⁵ = 645091883 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (645124621) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 107800 + ... + 113626.

It is an arithmetic number, because the mean of its divisors is an integer number (113199190).

Almost surely, 2^645124651 is an apocalyptic number.

645124651 is a deficient number, since it is larger than the sum of its proper divisors (34070489).

645124651 is an frugal number, since it uses more digits than its factorization.

645124651 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11673 (or 5846 counting only the distinct ones).

The product of its digits is 28800, while the sum is 34.

The square root of 645124651 is about 25399.3041440115. The cubic root of 645124651 is about 864.0679150967.

The spelling of 645124651 in words is "six hundred forty-five million, one hundred twenty-four thousand, six hundred fifty-one".