21556753163 has 16 divisors (see below), whose sum is σ = 24093096192. Its totient is φ = 19117644000.

The previous prime is 21556753139. The next prime is 21556753199. The reversal of 21556753163 is 36135765512.

It is a cyclic number.

It is not a de Polignac number, because 21556753163 - 2¹⁶ = 21556687627 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21556753103) 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, 360578 + ... + 416088.

It is an arithmetic number, because the mean of its divisors is an integer number (1505818512).

Almost surely, 2^21556753163 is an apocalyptic number.

21556753163 is a deficient number, since it is larger than the sum of its proper divisors (2536343029).

21556753163 is a wasteful number, since it uses less digits than its factorization.

21556753163 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 56386.

The product of its digits is 567000, while the sum is 44.

The spelling of 21556753163 in words is "twenty-one billion, five hundred fifty-six million, seven hundred fifty-three thousand, one hundred sixty-three".