31531225000 has 96 divisors (see below), whose sum is σ = 80615152800. Its totient is φ = 11465800000.

The previous prime is 31531224979. The next prime is 31531225001. The reversal of 31531225000 is 52213513.

It is a Harshad number since it is a multiple of its sum of digits (22).

It is not an unprimeable number, because it can be changed into a prime (31531225001) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 217671 + ... + 332329.

It is an arithmetic number, because the mean of its divisors is an integer number (839741175).

Almost surely, 2^31531225000 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 31531225000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40307576400).

31531225000 is an abundant number, since it is smaller than the sum of its proper divisors (49083927800).

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

31531225000 is a wasteful number, since it uses less digits than its factorization.

31531225000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 114701 (or 114677 counting only the distinct ones).

The product of its (nonzero) digits is 900, while the sum is 22.

Adding to 31531225000 its reverse (52213513), we get a palindrome (31583438513).

The spelling of 31531225000 in words is "thirty-one billion, five hundred thirty-one million, two hundred twenty-five thousand".