21080171969 has 4 divisors (see below), whose sum is σ = 21082835844. Its totient is φ = 21077508096.

The previous prime is 21080171963. The next prime is 21080171993. The reversal of 21080171969 is 96917108012.

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 17909130625 + 3171041344 = 133825^2 + 56312^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21080171969 is a prime.

It is a super-2 number, since 2×21080171969² (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 (21080171963) 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, 1320032 + ... + 1335905.

It is an arithmetic number, because the mean of its divisors is an integer number (5270708961).

Almost surely, 2^21080171969 is an apocalyptic number.

It is an amenable number.

21080171969 is a deficient number, since it is larger than the sum of its proper divisors (2663875).

21080171969 is an equidigital number, since it uses as much as digits as its factorization.

21080171969 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2663874.

The product of its (nonzero) digits is 54432, while the sum is 44.

The spelling of 21080171969 in words is "twenty-one billion, eighty million, one hundred seventy-one thousand, nine hundred sixty-nine".