31399000 has 64 divisors (see below), whose sum is σ = 77837760. Its totient is φ = 11814400.

The previous prime is 31398953. The next prime is 31399003. The reversal of 31399000 is 99313.

It is a Harshad number since it is a multiple of its sum of digits (25).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31399003) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 16077 + ... + 17923.

It is an arithmetic number, because the mean of its divisors is an integer number (1216215).

Almost surely, 2^31399000 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 31399000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38918880).

31399000 is an abundant number, since it is smaller than the sum of its proper divisors (46438760).

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

31399000 is a wasteful number, since it uses less digits than its factorization.

31399000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1885 (or 1871 counting only the distinct ones).

The product of its (nonzero) digits is 729, while the sum is 25.

The square root of 31399000 is about 5603.4810609120. The cubic root of 31399000 is about 315.4800775711.

The spelling of 31399000 in words is "thirty-one million, three hundred ninety-nine thousand".