21200120231 has 4 divisors (see below), whose sum is σ = 21200413200. Its totient is φ = 21199827264.

The previous prime is 21200120213. The next prime is 21200120237. The reversal of 21200120231 is 13202100212.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 21200120231 - 2⁶ = 21200120167 is a prime.

It is a super-2 number, since 2×21200120231² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21200120237) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 49175 + ... + 211703.

It is an arithmetic number, because the mean of its divisors is an integer number (5300103300).

Almost surely, 2^21200120231 is an apocalyptic number.

21200120231 is a deficient number, since it is larger than the sum of its proper divisors (292969).

21200120231 is a wasteful number, since it uses less digits than its factorization.

21200120231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 292968.

The product of its (nonzero) digits is 48, while the sum is 14.

Adding to 21200120231 its reverse (13202100212), we get a palindrome (34402220443).

It can be divided in two parts, 212001 and 20231, that added together give a palindrome (232232).

The spelling of 21200120231 in words is "twenty-one billion, two hundred million, one hundred twenty thousand, two hundred thirty-one".