21001211213223 has 32 divisors (see below), whose sum is σ = 28954662338560. Its totient is φ = 13525843799520.

The previous prime is 21001211213219. The next prime is 21001211213231. The reversal of 21001211213223 is 32231211210012.

It is not a de Polignac number, because 21001211213223 - 2² = 21001211213219 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21001211213223.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21001211203223) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 931595490 + ... + 931618032.

It is an arithmetic number, because the mean of its divisors is an integer number (904833198080).

Almost surely, 2^{21001211213223} is an apocalyptic number.

21001211213223 is a deficient number, since it is larger than the sum of its proper divisors (7953451125337).

21001211213223 is a wasteful number, since it uses less digits than its factorization.

21001211213223 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39379.

The product of its (nonzero) digits is 288, while the sum is 21.

Adding to 21001211213223 its reverse (32231211210012), we get a palindrome (53232422423235).

The spelling of 21001211213223 in words is "twenty-one trillion, one billion, two hundred eleven million, two hundred thirteen thousand, two hundred twenty-three".