21307525733 has 4 divisors (see below), whose sum is σ = 22946566188. Its totient is φ = 19668485280.

The previous prime is 21307525727. The next prime is 21307525753. The reversal of 21307525733 is 33752570312.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 9133051489 + 12174474244 = 95567^2 + 110338^2 .

It is a cyclic number.

It is not a de Polignac number, because 21307525733 - 2⁶ = 21307525669 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21307525753) 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, 819520208 + ... + 819520233.

It is an arithmetic number, because the mean of its divisors is an integer number (5736641547).

Almost surely, 2^21307525733 is an apocalyptic number.

It is an amenable number.

21307525733 is a deficient number, since it is larger than the sum of its proper divisors (1639040455).

21307525733 is a wasteful number, since it uses less digits than its factorization.

21307525733 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1639040454.

The product of its (nonzero) digits is 132300, while the sum is 38.

The spelling of 21307525733 in words is "twenty-one billion, three hundred seven million, five hundred twenty-five thousand, seven hundred thirty-three".