31121231000 has 128 divisors (see below), whose sum is σ = 76748031360. Its totient is φ = 11788480000.

The previous prime is 31121230993. The next prime is 31121231027. The reversal of 31121231000 is 13212113.

It is a super-2 number, since 2×31121231000² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 2316302 + ... + 2329698.

It is an arithmetic number, because the mean of its divisors is an integer number (599593995).

Almost surely, 2^31121231000 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 31121231000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38374015680).

31121231000 is an abundant number, since it is smaller than the sum of its proper divisors (45626800360).

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

31121231000 is a wasteful number, since it uses less digits than its factorization.

31121231000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13542 (or 13528 counting only the distinct ones).

The product of its (nonzero) digits is 36, while the sum is 14.

Adding to 31121231000 its reverse (13212113), we get a palindrome (31134443113).

The spelling of 31121231000 in words is "thirty-one billion, one hundred twenty-one million, two hundred thirty-one thousand".