21213020231 has 16 divisors (see below), whose sum is σ = 24336896640. Its totient is φ = 18327137760.

The previous prime is 21213020219. The next prime is 21213020233. The reversal of 21213020231 is 13202031212.

It is a cyclic number.

It is not a de Polignac number, because 21213020231 - 2³⁴ = 4033151047 is a prime.

It is a super-2 number, since 2×21213020231² (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 (21213020233) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 496865 + ... + 537866.

It is an arithmetic number, because the mean of its divisors is an integer number (1521056040).

Almost surely, 2^21213020231 is an apocalyptic number.

21213020231 is a deficient number, since it is larger than the sum of its proper divisors (3123876409).

21213020231 is a wasteful number, since it uses less digits than its factorization.

21213020231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1034846.

The product of its (nonzero) digits is 144, while the sum is 17.

Adding to 21213020231 its reverse (13202031212), we get a palindrome (34415051443).

The spelling of 21213020231 in words is "twenty-one billion, two hundred thirteen million, twenty thousand, two hundred thirty-one".