645769456 has 10 divisors (see below), whose sum is σ = 1251178352. Its totient is φ = 322884720.

The previous prime is 645769451. The next prime is 645769499. The reversal of 645769456 is 654967546.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645769451) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20180280 + ... + 20180311.

Almost surely, 2^645769456 is an apocalyptic number.

It is an amenable number.

645769456 is a deficient number, since it is larger than the sum of its proper divisors (605408896).

645769456 is a wasteful number, since it uses less digits than its factorization.

645769456 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40360599 (or 40360593 counting only the distinct ones).

The product of its digits is 5443200, while the sum is 52.

The square root of 645769456 is about 25411.9943333852. The cubic root of 645769456 is about 864.3556991644.

The spelling of 645769456 in words is "six hundred forty-five million, seven hundred sixty-nine thousand, four hundred fifty-six".