21089656569 has 16 divisors (see below), whose sum is σ = 28264169024. Its totient is φ = 13987512000.

The previous prime is 21089656519. The next prime is 21089656583. The reversal of 21089656569 is 96565698012.

It is not a de Polignac number, because 21089656569 - 2⁹ = 21089656057 is a prime.

It is a super-2 number, since 2×21089656569² (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 (21089656519) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2084487 + ... + 2094579.

It is an arithmetic number, because the mean of its divisors is an integer number (1766510564).

Almost surely, 2^21089656569 is an apocalyptic number.

It is an amenable number.

21089656569 is a deficient number, since it is larger than the sum of its proper divisors (7174512455).

21089656569 is a wasteful number, since it uses less digits than its factorization.

21089656569 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13608.

The product of its (nonzero) digits is 6998400, while the sum is 57.

The spelling of 21089656569 in words is "twenty-one billion, eighty-nine million, six hundred fifty-six thousand, five hundred sixty-nine".