31312000 has 128 divisors (see below), whose sum is σ = 82742400. Its totient is φ = 11750400.

The previous prime is 31311997. The next prime is 31312007. The reversal of 31312000 is 21313.

It is a tau number, because it is divible by the number of its divisors (128).

It is a Harshad number since it is a multiple of its sum of digits (10).

It is not an unprimeable number, because it can be changed into a prime (31312007) 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 15 ways as a sum of consecutive naturals, for example, 303949 + ... + 304051.

It is an arithmetic number, because the mean of its divisors is an integer number (646425).

Almost surely, 2^31312000 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 31312000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (41371200).

31312000 is an abundant number, since it is smaller than the sum of its proper divisors (51430400).

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

31312000 is a wasteful number, since it uses less digits than its factorization.

31312000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 151 (or 129 counting only the distinct ones).

The product of its (nonzero) digits is 18, while the sum is 10.

The square root of 31312000 is about 5595.7126445163. The cubic root of 31312000 is about 315.1884318119.

Adding to 31312000 its reverse (21313), we get a palindrome (31333313).

The spelling of 31312000 in words is "thirty-one million, three hundred twelve thousand".