646651451523 has 64 divisors (see below), whose sum is σ = 1122060386304. Its totient is φ = 321211440000.

The previous prime is 646651451483. The next prime is 646651451549. The reversal of 646651451523 is 325154156646.

It is a happy number.

It is not a de Polignac number, because 646651451523 - 2¹⁰ = 646651450499 is a prime.

It is not an unprimeable number, because it can be changed into a prime (646651451573) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 17519778 + ... + 17556648.

It is an arithmetic number, because the mean of its divisors is an integer number (17532193536).

Almost surely, 2^646651451523 is an apocalyptic number.

646651451523 is a deficient number, since it is larger than the sum of its proper divisors (475408934781).

646651451523 is a wasteful number, since it uses less digits than its factorization.

646651451523 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40216.

The product of its digits is 2592000, while the sum is 48.

The spelling of 646651451523 in words is "six hundred forty-six billion, six hundred fifty-one million, four hundred fifty-one thousand, five hundred twenty-three".