40399731 has 12 divisors (see below), whose sum is σ = 59094880. Its totient is φ = 26591760.

The previous prime is 40399721. The next prime is 40399739. The reversal of 40399731 is 13799304.

It is not a de Polignac number, because 40399731 - 2⁵ = 40399699 is a prime.

It is a super-2 number, since 2×40399731² = 3264276529744722, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (40399739) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 27700 + ... + 29121.

Almost surely, 2^40399731 is an apocalyptic number.

40399731 is a deficient number, since it is larger than the sum of its proper divisors (18695149).

40399731 is a wasteful number, since it uses less digits than its factorization.

40399731 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 56906 (or 56903 counting only the distinct ones).

The product of its (nonzero) digits is 20412, while the sum is 36.

The square root of 40399731 is about 6356.0782720165. The cubic root of 40399731 is about 343.1306327521.

The spelling of 40399731 in words is "forty million, three hundred ninety-nine thousand, seven hundred thirty-one".