21890172689 has 32 divisors (see below), whose sum is σ = 29893536000. Its totient is φ = 15500298240.

The previous prime is 21890172673. The next prime is 21890172709. The reversal of 21890172689 is 98627109812.

It is not a de Polignac number, because 21890172689 - 2⁴ = 21890172673 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 21890172689.

It is not an unprimeable number, because it can be changed into a prime (21890172659) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 250364 + ... + 326285.

It is an arithmetic number, because the mean of its divisors is an integer number (934173000).

Almost surely, 2^21890172689 is an apocalyptic number.

21890172689 is a gapful number since it is divisible by the number (29) formed by its first and last digit.

It is an amenable number.

21890172689 is a deficient number, since it is larger than the sum of its proper divisors (8003363311).

21890172689 is a wasteful number, since it uses less digits than its factorization.

21890172689 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 576713.

The product of its (nonzero) digits is 870912, while the sum is 53.

The spelling of 21890172689 in words is "twenty-one billion, eight hundred ninety million, one hundred seventy-two thousand, six hundred eighty-nine".