21312400213 has 6 divisors (see below), whose sum is σ = 23077924674. Its totient is φ = 19672984656.

The previous prime is 21312400189. The next prime is 21312400247. The reversal of 21312400213 is 31200421312.

It is a happy number.

It can be written as a sum of positive squares in 3 ways, for example, as 1879482609 + 19432917604 = 43353^2 + 139402^2 .

It is not a de Polignac number, because 21312400213 - 2⁹ = 21312399701 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21312400253) by changing a digit.

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 5 ways as a sum of consecutive naturals, for example, 63054270 + ... + 63054607.

It is an arithmetic number, because the mean of its divisors is an integer number (3846320779).

Almost surely, 2^21312400213 is an apocalyptic number.

It is an amenable number.

21312400213 is a deficient number, since it is larger than the sum of its proper divisors (1765524461).

21312400213 is a wasteful number, since it uses less digits than its factorization.

21312400213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 126108903 (or 126108890 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 19.

Adding to 21312400213 its reverse (31200421312), we get a palindrome (52512821525).

The spelling of 21312400213 in words is "twenty-one billion, three hundred twelve million, four hundred thousand, two hundred thirteen".