31396840 has 32 divisors (see below), whose sum is σ = 73716480. Its totient is φ = 12012352.

The previous prime is 31396823. The next prime is 31396843. The reversal of 31396840 is 4869313.

It is a junction number, because it is equal to n+sod(n) for n = 31396796 and 31396805.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31396843) 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, 16144 + ... + 17983.

It is an arithmetic number, because the mean of its divisors is an integer number (2303640).

Almost surely, 2^31396840 is an apocalyptic number.

It is an amenable number.

31396840 is an abundant number, since it is smaller than the sum of its proper divisors (42319640).

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

31396840 is a wasteful number, since it uses less digits than its factorization.

31396840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34161 (or 34157 counting only the distinct ones).

The product of its (nonzero) digits is 15552, while the sum is 34.

The square root of 31396840 is about 5603.2883202634. The cubic root of 31396840 is about 315.4728432367.

The spelling of 31396840 in words is "thirty-one million, three hundred ninety-six thousand, eight hundred forty".