645724065 has 32 divisors (see below), whose sum is σ = 1185396480. Its totient is φ = 294027264.

The previous prime is 645724049. The next prime is 645724097. The reversal of 645724065 is 560427546.

It is not a de Polignac number, because 645724065 - 2⁴ = 645724049 is a prime.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 15021 + ... + 38949.

It is an arithmetic number, because the mean of its divisors is an integer number (37043640).

Almost surely, 2^645724065 is an apocalyptic number.

It is an amenable number.

645724065 is a deficient number, since it is larger than the sum of its proper divisors (539672415).

645724065 is a wasteful number, since it uses less digits than its factorization.

645724065 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24201.

The product of its (nonzero) digits is 201600, while the sum is 39.

The square root of 645724065 is about 25411.1012158072. The cubic root of 645724065 is about 864.3354468961.

The spelling of 645724065 in words is "six hundred forty-five million, seven hundred twenty-four thousand, sixty-five".