31399680 has 288 divisors, whose sum is σ = 117440064. Its totient is φ = 7077888.

The previous prime is 31399661. The next prime is 31399729. The reversal of 31399680 is 8699313.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 848622 + ... + 848658.

It is an arithmetic number, because the mean of its divisors is an integer number (407778).

Almost surely, 2^31399680 is an apocalyptic number.

31399680 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 31399680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (58720032).

31399680 is an abundant number, since it is smaller than the sum of its proper divisors (86040384).

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

31399680 is a wasteful number, since it uses less digits than its factorization.

31399680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 91 (or 77 counting only the distinct ones).

The product of its (nonzero) digits is 34992, while the sum is 39.

The square root of 31399680 is about 5603.5417371516. The cubic root of 31399680 is about 315.4823549781.

The spelling of 31399680 in words is "thirty-one million, three hundred ninety-nine thousand, six hundred eighty".