2121200400 has 120 divisors (see below), whose sum is σ = 7412677344. Its totient is φ = 514227200.

The previous prime is 2121200399. The next prime is 2121200401. The reversal of 2121200400 is 40021212.

It is an interprime number because it is at equal distance from previous prime (2121200399) and next prime (2121200401).

It is a tau number, because it is divible by the number of its divisors (120).

It is a super-2 number, since 2×2121200400² = 8998982273920320000, which contains 22 as substring.

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

It is not an unprimeable number, because it can be changed into a prime (2121200401) 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, 67149 + ... + 93548.

Almost surely, 2^2121200400 is an apocalyptic number.

2121200400 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

2121200400 is an abundant number, since it is smaller than the sum of its proper divisors (5291476944).

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

2121200400 is a wasteful number, since it uses less digits than its factorization.

2121200400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 160729 (or 160718 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 12.

The square root of 2121200400 is about 46056.4913991502. The cubic root of 2121200400 is about 1284.8740760898.

Adding to 2121200400 its reverse (40021212), we get a palindrome (2161221612).

The spelling of 2121200400 in words is "two billion, one hundred twenty-one million, two hundred thousand, four hundred".