21023321236 has 24 divisors (see below), whose sum is σ = 37321591104. Its totient is φ = 10360109760.

The previous prime is 21023321203. The next prime is 21023321237. The reversal of 21023321236 is 63212332012.

It is a self number, because there is not a number n which added to its sum of digits gives 21023321236.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21023321237) 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, 964191 + ... + 985753.

It is an arithmetic number, because the mean of its divisors is an integer number (1555066296).

Almost surely, 2^21023321236 is an apocalyptic number.

It is an amenable number.

21023321236 is a deficient number, since it is larger than the sum of its proper divisors (16298269868).

21023321236 is a wasteful number, since it uses less digits than its factorization.

21023321236 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25071 (or 25069 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 25.

Adding to 21023321236 its reverse (63212332012), we get a palindrome (84235653248).

The spelling of 21023321236 in words is "twenty-one billion, twenty-three million, three hundred twenty-one thousand, two hundred thirty-six".