31940405 has 12 divisors (see below), whose sum is σ = 44586540. Its totient is φ = 21901824.

The previous prime is 31940383. The next prime is 31940407. The reversal of 31940405 is 50404913.

It can be written as a sum of positive squares in 2 ways, for example, as 9746884 + 22193521 = 3122^2 + 4711^2 .

It is not a de Polignac number, because 31940405 - 2¹⁰ = 31939381 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31940407) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 64940 + ... + 65429.

It is an arithmetic number, because the mean of its divisors is an integer number (3715545).

Almost surely, 2^31940405 is an apocalyptic number.

31940405 is a gapful number since it is divisible by the number (35) formed by its first and last digit.

It is an amenable number.

31940405 is a deficient number, since it is larger than the sum of its proper divisors (12646135).

31940405 is a wasteful number, since it uses less digits than its factorization.

31940405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 130388 (or 130381 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 26.

The square root of 31940405 is about 5651.5842911523. The cubic root of 31940405 is about 317.2830021579.

The spelling of 31940405 in words is "thirty-one million, nine hundred forty thousand, four hundred five".