21600921761 has 16 divisors (see below), whose sum is σ = 22998144000. Its totient is φ = 20230421328.

The previous prime is 21600921751. The next prime is 21600921767. The reversal of 21600921761 is 16712900612.

It is a cyclic number.

It is not a de Polignac number, because 21600921761 - 2⁶ = 21600921697 is a prime.

It is a super-2 number, since 2×21600921761² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21600921767) 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, 1163030 + ... + 1181456.

It is an arithmetic number, because the mean of its divisors is an integer number (1437384000).

Almost surely, 2^21600921761 is an apocalyptic number.

It is an amenable number.

21600921761 is a deficient number, since it is larger than the sum of its proper divisors (1397222239).

21600921761 is a wasteful number, since it uses less digits than its factorization.

21600921761 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19148.

The product of its (nonzero) digits is 9072, while the sum is 35.

The spelling of 21600921761 in words is "twenty-one billion, six hundred million, nine hundred twenty-one thousand, seven hundred sixty-one".