646531523 has 4 divisors (see below), whose sum is σ = 705307128. Its totient is φ = 587755920.

The previous prime is 646531519. The next prime is 646531537. The reversal of 646531523 is 325135646.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 646531523 - 2² = 646531519 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (646530523) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 29387786 + ... + 29387807.

It is an arithmetic number, because the mean of its divisors is an integer number (176326782).

Almost surely, 2^646531523 is an apocalyptic number.

646531523 is a deficient number, since it is larger than the sum of its proper divisors (58775605).

646531523 is a wasteful number, since it uses less digits than its factorization.

646531523 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 58775604.

The product of its digits is 64800, while the sum is 35.

The square root of 646531523 is about 25426.9841507010. The cubic root of 646531523 is about 864.6955717565.

The spelling of 646531523 in words is "six hundred forty-six million, five hundred thirty-one thousand, five hundred twenty-three".