40991631 has 16 divisors (see below), whose sum is σ = 56249856. Its totient is φ = 26541216.

The previous prime is 40991627. The next prime is 40991647. The reversal of 40991631 is 13619904.

It is not a de Polignac number, because 40991631 - 2² = 40991627 is a prime.

It is a super-2 number, since 2×40991631² = 3360627624080322, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 40991592 and 40991601.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (40991651) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 15126 + ... + 17628.

It is an arithmetic number, because the mean of its divisors is an integer number (3515616).

Almost surely, 2^40991631 is an apocalyptic number.

40991631 is a deficient number, since it is larger than the sum of its proper divisors (15258225).

40991631 is a wasteful number, since it uses less digits than its factorization.

40991631 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2662.

The product of its (nonzero) digits is 5832, while the sum is 33.

The square root of 40991631 is about 6402.4706949739. The cubic root of 40991631 is about 344.7982605474.

The spelling of 40991631 in words is "forty million, nine hundred ninety-one thousand, six hundred thirty-one".