31121001100 has 144 divisors (see below), whose sum is σ = 79122935808. Its totient is φ = 10403976960.

The previous prime is 31121001077. The next prime is 31121001203. The reversal of 31121001100 is 110012113.

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

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 6193189 + ... + 6198211.

It is an arithmetic number, because the mean of its divisors is an integer number (549464832).

Almost surely, 2^31121001100 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 31121001100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39561467904).

31121001100 is an abundant number, since it is smaller than the sum of its proper divisors (48001934708).

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

31121001100 is a wasteful number, since it uses less digits than its factorization.

31121001100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5264 (or 5257 counting only the distinct ones).

The product of its (nonzero) digits is 6, while the sum is 10.

Adding to 31121001100 its reverse (110012113), we get a palindrome (31231013213).

The spelling of 31121001100 in words is "thirty-one billion, one hundred twenty-one million, one thousand, one hundred".