21213613213204 has 24 divisors (see below), whose sum is σ = 37180866367008. Its totient is φ = 10590511864800.

The previous prime is 21213613213201. The next prime is 21213613213207. The reversal of 21213613213204 is 40231231631212.

It is an interprime number because it is at equal distance from previous prime (21213613213201) and next prime (21213613213207).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21213613213201) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 25394179 + ... + 26216245.

It is an arithmetic number, because the mean of its divisors is an integer number (1549202765292).

Almost surely, 2^{21213613213204} is an apocalyptic number.

It is an amenable number.

21213613213204 is a deficient number, since it is larger than the sum of its proper divisors (15967253153804).

21213613213204 is a wasteful number, since it uses less digits than its factorization.

21213613213204 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 831975 (or 831973 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 31.

Adding to 21213613213204 its reverse (40231231631212), we get a palindrome (61444844844416).

The spelling of 21213613213204 in words is "twenty-one trillion, two hundred thirteen billion, six hundred thirteen million, two hundred thirteen thousand, two hundred four".