21011223213 has 24 divisors (see below), whose sum is σ = 30673244160. Its totient is φ = 13858293600.

The previous prime is 21011223209. The next prime is 21011223217. The reversal of 21011223213 is 31232211012.

It is an interprime number because it is at equal distance from previous prime (21011223209) and next prime (21011223217).

It is not a de Polignac number, because 21011223213 - 2² = 21011223209 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21011223217) 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 23 ways as a sum of consecutive naturals, for example, 1300020 + ... + 1316082.

It is an arithmetic number, because the mean of its divisors is an integer number (1278051840).

Almost surely, 2^21011223213 is an apocalyptic number.

It is an amenable number.

21011223213 is a deficient number, since it is larger than the sum of its proper divisors (9662020947).

21011223213 is a wasteful number, since it uses less digits than its factorization.

21011223213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17609 (or 17606 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

Adding to 21011223213 its reverse (31232211012), we get a palindrome (52243434225).

The spelling of 21011223213 in words is "twenty-one billion, eleven million, two hundred twenty-three thousand, two hundred thirteen".