21302733561 has 16 divisors (see below), whose sum is σ = 29724033024. Its totient is φ = 13545188624.

The previous prime is 21302733559. The next prime is 21302733589. The reversal of 21302733561 is 16533720312.

It is a cyclic number.

It is not a de Polignac number, because 21302733561 - 2¹ = 21302733559 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21302733521) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 420921 + ... + 468806.

It is an arithmetic number, because the mean of its divisors is an integer number (1857752064).

Almost surely, 2^21302733561 is an apocalyptic number.

It is an amenable number.

21302733561 is a deficient number, since it is larger than the sum of its proper divisors (8421299463).

21302733561 is a wasteful number, since it uses less digits than its factorization.

21302733561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 890100.

The product of its (nonzero) digits is 22680, while the sum is 33.

The spelling of 21302733561 in words is "twenty-one billion, three hundred two million, seven hundred thirty-three thousand, five hundred sixty-one".