645015894 has 16 divisors (see below), whose sum is σ = 1324897968. Its totient is φ = 209194272.

The previous prime is 645015871. The next prime is 645015911. The reversal of 645015894 is 498510546.

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, 1452517 + ... + 1452960.

It is an arithmetic number, because the mean of its divisors is an integer number (82806123).

Almost surely, 2^645015894 is an apocalyptic number.

645015894 is an abundant number, since it is smaller than the sum of its proper divisors (679882074).

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

645015894 is a wasteful number, since it uses less digits than its factorization.

645015894 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2905519.

The product of its (nonzero) digits is 172800, while the sum is 42.

The square root of 645015894 is about 25397.1631092923. The cubic root of 645015894 is about 864.0193566694.

The spelling of 645015894 in words is "six hundred forty-five million, fifteen thousand, eight hundred ninety-four".