663291531 has 32 divisors (see below), whose sum is σ = 1159270400. Its totient is φ = 366793920.

The previous prime is 663291467. The next prime is 663291569. The reversal of 663291531 is 135192366.

663291531 is a `hidden beast` number, since 6 + 6 + 32 + 91 + 531 = 666.

It is not a de Polignac number, because 663291531 - 2⁶ = 663291467 is a prime.

It is a super-2 number, since 2×663291531² = 879911310192647922, which contains 22 as substring.

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (663291571) 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 31 ways as a sum of consecutive naturals, for example, 50746 + ... + 62463.

It is an arithmetic number, because the mean of its divisors is an integer number (36227200).

Almost surely, 2^663291531 is an apocalyptic number.

663291531 is a deficient number, since it is larger than the sum of its proper divisors (495978869).

663291531 is a wasteful number, since it uses less digits than its factorization.

663291531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 113256 (or 113250 counting only the distinct ones).

The product of its digits is 29160, while the sum is 36.

The square root of 663291531 is about 25754.4468199183. The cubic root of 663291531 is about 872.1037435662.

The spelling of 663291531 in words is "six hundred sixty-three million, two hundred ninety-one thousand, five hundred thirty-one".