21213403210 has 16 divisors (see below), whose sum is σ = 38185823592. Its totient is φ = 8484984000.

The previous prime is 21213403207. The next prime is 21213403231. The reversal of 21213403210 is 1230431212.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 8476700761 + 12736702449 = 92069^2 + 112857^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 341560 + ... + 398860.

Almost surely, 2^21213403210 is an apocalyptic number.

21213403210 is a deficient number, since it is larger than the sum of its proper divisors (16972420382).

21213403210 is a wasteful number, since it uses less digits than its factorization.

21213403210 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 94329.

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

Adding to 21213403210 its reverse (1230431212), we get a palindrome (22443834422).

The spelling of 21213403210 in words is "twenty-one billion, two hundred thirteen million, four hundred three thousand, two hundred ten".