645515438 has 16 divisors (see below), whose sum is σ = 978516720. Its totient is φ = 319353216.

The previous prime is 645515413. The next prime is 645515459. The reversal of 645515438 is 834515546.

It is a junction number, because it is equal to n+sod(n) for n = 645515395 and 645515404.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 150893 + ... + 155111.

It is an arithmetic number, because the mean of its divisors is an integer number (61157295).

Almost surely, 2^645515438 is an apocalyptic number.

645515438 is a deficient number, since it is larger than the sum of its proper divisors (333001282).

645515438 is a wasteful number, since it uses less digits than its factorization.

645515438 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5011.

The product of its digits is 288000, while the sum is 41.

The square root of 645515438 is about 25406.9958476007. The cubic root of 645515438 is about 864.2423508174.

The spelling of 645515438 in words is "six hundred forty-five million, five hundred fifteen thousand, four hundred thirty-eight".