40139831 has 4 divisors (see below), whose sum is σ = 40165632. Its totient is φ = 40114032.

The previous prime is 40139819. The next prime is 40139843. The reversal of 40139831 is 13893104.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (40139819) and next prime (40139843).

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-40139831 is a prime.

It is a super-2 number, since 2×40139831² = 3222412065417122, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 40139794 and 40139803.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (40139131) 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, 10406 + ... + 13731.

It is an arithmetic number, because the mean of its divisors is an integer number (10041408).

Almost surely, 2^40139831 is an apocalyptic number.

40139831 is a deficient number, since it is larger than the sum of its proper divisors (25801).

40139831 is a wasteful number, since it uses less digits than its factorization.

40139831 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25800.

The product of its (nonzero) digits is 2592, while the sum is 29.

The square root of 40139831 is about 6335.6002872656. The cubic root of 40139831 is about 342.3932386091.

The spelling of 40139831 in words is "forty million, one hundred thirty-nine thousand, eight hundred thirty-one".