645692523 has 16 divisors (see below), whose sum is σ = 1035697920. Its totient is φ = 349547616.

The previous prime is 645692507. The next prime is 645692539. The reversal of 645692523 is 325296546.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (645692507) and next prime (645692539).

It is not a de Polignac number, because 645692523 - 2⁴ = 645692507 is a prime.

It is not an unprimeable number, because it can be changed into a prime (645692563) 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, 808740 + ... + 809537.

It is an arithmetic number, because the mean of its divisors is an integer number (64731120).

Almost surely, 2^645692523 is an apocalyptic number.

645692523 is a deficient number, since it is larger than the sum of its proper divisors (390005397).

645692523 is a wasteful number, since it uses less digits than its factorization.

645692523 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1618306.

The product of its digits is 388800, while the sum is 42.

The square root of 645692523 is about 25410.4805739679. The cubic root of 645692523 is about 864.3213731278.

The spelling of 645692523 in words is "six hundred forty-five million, six hundred ninety-two thousand, five hundred twenty-three".