21312400206 has 32 divisors (see below), whose sum is σ = 44907402240. Its totient is φ = 6724353024.

The previous prime is 21312400189. The next prime is 21312400247. The reversal of 21312400206 is 60200421312.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 50371 + ... + 212513.

It is an arithmetic number, because the mean of its divisors is an integer number (1403356320).

Almost surely, 2^21312400206 is an apocalyptic number.

21312400206 is an abundant number, since it is smaller than the sum of its proper divisors (23595002034).

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

21312400206 is a wasteful number, since it uses less digits than its factorization.

21312400206 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 163320.

The product of its (nonzero) digits is 576, while the sum is 21.

Adding to 21312400206 its reverse (60200421312), we get a palindrome (81512821518).

The spelling of 21312400206 in words is "twenty-one billion, three hundred twelve million, four hundred thousand, two hundred six".