31213211100 has 72 divisors (see below), whose sum is σ = 92751073968. Its totient is φ = 8098560000.

The previous prime is 31213211069. The next prime is 31213211101. The reversal of 31213211100 is 111231213.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 31213211100.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31213211101) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1394901 + ... + 1417100.

Almost surely, 2^31213211100 is an apocalyptic number.

31213211100 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

31213211100 is an abundant number, since it is smaller than the sum of its proper divisors (61537862868).

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

31213211100 is a wasteful number, since it uses less digits than its factorization.

31213211100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2812055 (or 2812048 counting only the distinct ones).

The product of its (nonzero) digits is 36, while the sum is 15.

Adding to 31213211100 its reverse (111231213), we get a palindrome (31324442313).

The spelling of 31213211100 in words is "thirty-one billion, two hundred thirteen million, two hundred eleven thousand, one hundred".