31399368 has 128 divisors (see below), whose sum is σ = 105477120. Its totient is φ = 7522560.

The previous prime is 31399367. The next prime is 31399369. The reversal of 31399368 is 86399313.

It is an interprime number because it is at equal distance from previous prime (31399367) and next prime (31399369).

It is a Harshad number since it is a multiple of its sum of digits (42).

It is not an unprimeable number, because it can be changed into a prime (31399367) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 23371 + ... + 24677.

It is an arithmetic number, because the mean of its divisors is an integer number (824040).

Almost surely, 2^31399368 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 31399368, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (52738560).

31399368 is an abundant number, since it is smaller than the sum of its proper divisors (74077752).

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

31399368 is a wasteful number, since it uses less digits than its factorization.

31399368 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1347 (or 1343 counting only the distinct ones).

The product of its digits is 104976, while the sum is 42.

The square root of 31399368 is about 5603.5138975468. The cubic root of 31399368 is about 315.4813100542.

Subtracting 31399368 from its reverse (86399313), we obtain a palindrome (54999945).

It can be divided in two parts, 313 and 99368, that added together give a triangular number (99681 = T₄₄₆).

The spelling of 31399368 in words is "thirty-one million, three hundred ninety-nine thousand, three hundred sixty-eight".