31391420 has 24 divisors (see below), whose sum is σ = 69392400. Its totient is φ = 11895552.

The previous prime is 31391383. The next prime is 31391447. The reversal of 31391420 is 2419313.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 40925 + ... + 41684.

It is an arithmetic number, because the mean of its divisors is an integer number (2891350).

Almost surely, 2^31391420 is an apocalyptic number.

It is an amenable number.

31391420 is an abundant number, since it is smaller than the sum of its proper divisors (38000980).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

31391420 is a wasteful number, since it uses less digits than its factorization.

31391420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 82637 (or 82635 counting only the distinct ones).

The product of its (nonzero) digits is 648, while the sum is 23.

The square root of 31391420 is about 5602.8046548135. The cubic root of 31391420 is about 315.4546889553.

The spelling of 31391420 in words is "thirty-one million, three hundred ninety-one thousand, four hundred twenty".