121031211990 has 128 divisors (see below), whose sum is σ = 320190216192. Its totient is φ = 29093137920.

The previous prime is 121031211989. The next prime is 121031212031. The reversal of 121031211990 is 99112130121.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 8442969 + ... + 8457291.

It is an arithmetic number, because the mean of its divisors is an integer number (2501486064).

Almost surely, 2^121031211990 is an apocalyptic number.

121031211990 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 121031211990, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (160095108096).

121031211990 is an abundant number, since it is smaller than the sum of its proper divisors (199159004202).

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

121031211990 is a wasteful number, since it uses less digits than its factorization.

121031211990 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14854.

The product of its (nonzero) digits is 972, while the sum is 30.

The spelling of 121031211990 in words is "one hundred twenty-one billion, thirty-one million, two hundred eleven thousand, nine hundred ninety".