645538718 has 32 divisors (see below), whose sum is σ = 1114179840. Its totient is φ = 277421760.

The previous prime is 645538711. The next prime is 645538721. The reversal of 645538718 is 817835546.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645538711) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 256655 + ... + 259157.

It is an arithmetic number, because the mean of its divisors is an integer number (34818120).

Almost surely, 2^645538718 is an apocalyptic number.

645538718 is a deficient number, since it is larger than the sum of its proper divisors (468641122).

645538718 is a wasteful number, since it uses less digits than its factorization.

645538718 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3152.

The product of its digits is 806400, while the sum is 47.

The square root of 645538718 is about 25407.4539850021. The cubic root of 645538718 is about 864.2527400965.

The spelling of 645538718 in words is "six hundred forty-five million, five hundred thirty-eight thousand, seven hundred eighteen".