213122100 has 72 divisors (see below), whose sum is σ = 631709568. Its totient is φ = 55443200.

The previous prime is 213122099. The next prime is 213122137. The reversal of 213122100 is 1221312.

It is a Harshad number since it is a multiple of its sum of digits (12).

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, 3637 + ... + 20963.

It is an arithmetic number, because the mean of its divisors is an integer number (8773744).

Almost surely, 2^213122100 is an apocalyptic number.

213122100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 213122100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (315854784).

213122100 is an abundant number, since it is smaller than the sum of its proper divisors (418587468).

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

213122100 is a wasteful number, since it uses less digits than its factorization.

213122100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17385 (or 17378 counting only the distinct ones).

The product of its (nonzero) digits is 24, while the sum is 12.

The square root of 213122100 is about 14598.7019970955. The cubic root of 213122100 is about 597.3233548182.

Adding to 213122100 its reverse (1221312), we get a palindrome (214343412).

The spelling of 213122100 in words is "two hundred thirteen million, one hundred twenty-two thousand, one hundred".