9891631 has 4 divisors (see below), whose sum is σ = 9898200. Its totient is φ = 9885064.

The previous prime is 9891613. The next prime is 9891653. The reversal of 9891631 is 1361989.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-9891631 is a prime.

It is a super-2 number, since 2×9891631² = 195688727680322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9891601) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 225 + ... + 4453.

It is an arithmetic number, because the mean of its divisors is an integer number (2474550).

Almost surely, 2^9891631 is an apocalyptic number.

9891631 is a deficient number, since it is larger than the sum of its proper divisors (6569).

9891631 is a wasteful number, since it uses less digits than its factorization.

9891631 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6568.

The product of its digits is 11664, while the sum is 37.

The square root of 9891631 is about 3145.0963419266. The cubic root of 9891631 is about 214.6623942520.

The spelling of 9891631 in words is "nine million, eight hundred ninety-one thousand, six hundred thirty-one".