645726716 has 12 divisors (see below), whose sum is σ = 1133438040. Its totient is φ = 321887280.

The previous prime is 645726707. The next prime is 645726721. The reversal of 645726716 is 617627546.

It is a super-2 number, since 2×645726716² = 833925983512289312, which contains 22 as substring.

It is a hoax number, since the sum of its digits (44) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 242531 + ... + 245178.

It is an arithmetic number, because the mean of its divisors is an integer number (94453170).

Almost surely, 2^645726716 is an apocalyptic number.

It is an amenable number.

645726716 is a deficient number, since it is larger than the sum of its proper divisors (487711324).

645726716 is a wasteful number, since it uses less digits than its factorization.

645726716 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 488044 (or 488042 counting only the distinct ones).

The product of its digits is 423360, while the sum is 44.

The square root of 645726716 is about 25411.1533779953. The cubic root of 645726716 is about 864.3366297285.

The spelling of 645726716 in words is "six hundred forty-five million, seven hundred twenty-six thousand, seven hundred sixteen".