31021221000000 has 784 divisors, whose sum is σ = 127911492711936. Its totient is φ = 6445920000000.

The previous prime is 31021220999963. The next prime is 31021221000037. The reversal of 31021221000000 is 12212013.

It is an interprime number because it is at equal distance from previous prime (31021220999963) and next prime (31021221000037).

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a self number, because there is not a number n which added to its sum of digits gives 31021221000000.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 111 ways as a sum of consecutive naturals, for example, 230932855 + ... + 231067145.

Almost surely, 2^{31021221000000} is an apocalyptic number.

31021221000000 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 31021221000000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (63955746355968).

31021221000000 is an abundant number, since it is smaller than the sum of its proper divisors (96890271711936).

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

31021221000000 is an equidigital number, since it uses as much as digits as its factorization.

31021221000000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 134354 (or 134319 counting only the distinct ones).

The product of its (nonzero) digits is 24, while the sum is 12.

Adding to 31021221000000 its reverse (12212013), we get a palindrome (31021233212013).

The spelling of 31021221000000 in words is "thirty-one trillion, twenty-one billion, two hundred twenty-one million", and thus it is an aban number.