21326806501 has 24 divisors (see below), whose sum is σ = 29145934944. Its totient is φ = 15339955680.

The previous prime is 21326806499. The next prime is 21326806541. The reversal of 21326806501 is 10560862312.

It is not a de Polignac number, because 21326806501 - 2¹ = 21326806499 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21326806541) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1514815 + ... + 1528828.

It is an arithmetic number, because the mean of its divisors is an integer number (1214413956).

Almost surely, 2^21326806501 is an apocalyptic number.

It is an amenable number.

21326806501 is a deficient number, since it is larger than the sum of its proper divisors (7819128443).

21326806501 is a wasteful number, since it uses less digits than its factorization.

21326806501 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3043681 (or 3043674 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 34.

The spelling of 21326806501 in words is "twenty-one billion, three hundred twenty-six million, eight hundred six thousand, five hundred one".