31397120 has 72 divisors (see below), whose sum is σ = 79225440. Its totient is φ = 11888640.

The previous prime is 31397083. The next prime is 31397129. The reversal of 31397120 is 2179313.

It is a self number, because there is not a number n which added to its sum of digits gives 31397120.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31397129) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 23675 + ... + 24965.

Almost surely, 2^31397120 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 31397120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39612720).

31397120 is an abundant number, since it is smaller than the sum of its proper divisors (47828320).

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

31397120 is a wasteful number, since it uses less digits than its factorization.

31397120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1331 (or 1317 counting only the distinct ones).

The product of its (nonzero) digits is 1134, while the sum is 26.

The square root of 31397120 is about 5603.3133055363. The cubic root of 31397120 is about 315.4737810395.

The spelling of 31397120 in words is "thirty-one million, three hundred ninety-seven thousand, one hundred twenty".