31121100100 has 18 divisors (see below), whose sum is σ = 67532787434. Its totient is φ = 12448440000.

The previous prime is 31121100091. The next prime is 31121100163. The reversal of 31121100100 is 100112113.

It can be written as a sum of positive squares in 3 ways, for example, as 8711608896 + 22409491204 = 93336^2 + 149698^2 .

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 5 ways as a sum of consecutive naturals, for example, 155605401 + ... + 155605600.

Almost surely, 2^31121100100 is an apocalyptic number.

It is an amenable number.

31121100100 is an abundant number, since it is smaller than the sum of its proper divisors (36411687334).

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

31121100100 is a wasteful number, since it uses less digits than its factorization.

31121100100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 311211015 (or 311211008 counting only the distinct ones).

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

Adding to 31121100100 its reverse (100112113), we get a palindrome (31221212213).

The spelling of 31121100100 in words is "thirty-one billion, one hundred twenty-one million, one hundred thousand, one hundred".