213121211100 has 72 divisors (see below), whose sum is σ = 704720811648. Its totient is φ = 48713419200.

The previous prime is 213121211081. The next prime is 213121211111. The reversal of 213121211100 is 1112121312.

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 213121211100.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 50741046 + ... + 50745245.

Almost surely, 2^213121211100 is an apocalyptic number.

213121211100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

213121211100 is an abundant number, since it is smaller than the sum of its proper divisors (491599600548).

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

213121211100 is a wasteful number, since it uses less digits than its factorization.

213121211100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 101486315 (or 101486308 counting only the distinct ones).

The product of its (nonzero) digits is 24, while the sum is 15.

Adding to 213121211100 its reverse (1112121312), we get a palindrome (214233332412).

The spelling of 213121211100 in words is "two hundred thirteen billion, one hundred twenty-one million, two hundred eleven thousand, one hundred".