21056660533 has 8 divisors (see below), whose sum is σ = 21245126336. Its totient is φ = 20868840000.

The previous prime is 21056660531. The next prime is 21056660551. The reversal of 21056660533 is 33506665012.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21056660533 - 2¹ = 21056660531 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21056660492 and 21056660501.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21056660531) 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, 95643 + ... + 226408.

It is an arithmetic number, because the mean of its divisors is an integer number (2655640792).

Almost surely, 2^21056660533 is an apocalyptic number.

It is an amenable number.

21056660533 is a deficient number, since it is larger than the sum of its proper divisors (188465803).

21056660533 is a wasteful number, since it uses less digits than its factorization.

21056660533 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 322635.

The product of its (nonzero) digits is 97200, while the sum is 37.

The spelling of 21056660533 in words is "twenty-one billion, fifty-six million, six hundred sixty thousand, five hundred thirty-three".