39991131 has 8 divisors (see below), whose sum is σ = 59246160. Its totient is φ = 26660736.

The previous prime is 39991129. The next prime is 39991139. The reversal of 39991131 is 13119993.

It is not a de Polignac number, because 39991131 - 2¹ = 39991129 is a prime.

It is a super-2 number, since 2×39991131² = 3198581117318322, which contains 22 as substring.

It is a nude number because it is divisible by every one of its digits.

It is not an unprimeable number, because it can be changed into a prime (39991139) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 740550 + ... + 740603.

It is an arithmetic number, because the mean of its divisors is an integer number (7405770).

Almost surely, 2^39991131 is an apocalyptic number.

39991131 is a deficient number, since it is larger than the sum of its proper divisors (19255029).

39991131 is a wasteful number, since it uses less digits than its factorization.

39991131 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1481162 (or 1481156 counting only the distinct ones).

The product of its digits is 6561, while the sum is 36.

The square root of 39991131 is about 6323.8541254523. The cubic root of 39991131 is about 341.9699111725.

The spelling of 39991131 in words is "thirty-nine million, nine hundred ninety-one thousand, one hundred thirty-one".