21207023072 has 24 divisors (see below), whose sum is σ = 41764539600. Its totient is φ = 10600155904.

The previous prime is 21207023059. The next prime is 21207023077. The reversal of 21207023072 is 27032070212.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21207023077) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 572 + ... + 205947.

It is an arithmetic number, because the mean of its divisors is an integer number (1740189150).

Almost surely, 2^21207023072 is an apocalyptic number.

It is an amenable number.

21207023072 is a deficient number, since it is larger than the sum of its proper divisors (20557516528).

21207023072 is a wasteful number, since it uses less digits than its factorization.

21207023072 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 209738 (or 209730 counting only the distinct ones).

The product of its (nonzero) digits is 2352, while the sum is 26.

Adding to 21207023072 its reverse (27032070212), we get a palindrome (48239093284).

The spelling of 21207023072 in words is "twenty-one billion, two hundred seven million, twenty-three thousand, seventy-two".