646331631 has 8 divisors (see below), whose sum is σ = 940118784. Its totient is φ = 391716120.

The previous prime is 646331603. The next prime is 646331641. The reversal of 646331631 is 136133646.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 646331631 - 2¹⁹ = 645807343 is a prime.

It is a super-2 number, since 2×646331631² = 835489154462240322, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (33), and also a Moran number because the ratio is a prime number: 19585807 = 646331631 / (6 + 4 + 6 + 3 + 3 + 1 + 6 + 3 + 1).

It is a junction number, because it is equal to n+sod(n) for n = 646331592 and 646331601.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (646331641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9792871 + ... + 9792936.

It is an arithmetic number, because the mean of its divisors is an integer number (117514848).

Almost surely, 2^646331631 is an apocalyptic number.

646331631 is a deficient number, since it is larger than the sum of its proper divisors (293787153).

646331631 is a wasteful number, since it uses less digits than its factorization.

646331631 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19585821.

The product of its digits is 23328, while the sum is 33.

The square root of 646331631 is about 25423.0531408012. The cubic root of 646331631 is about 864.6064482117.

The spelling of 646331631 in words is "six hundred forty-six million, three hundred thirty-one thousand, six hundred thirty-one".