21995057189 has 4 divisors (see below), whose sum is σ = 25137208224. Its totient is φ = 18852906156.

The previous prime is 21995057167. The next prime is 21995057209. The reversal of 21995057189 is 98175059912.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 21995057189 - 2⁸ = 21995056933 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21995056189) 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, 1571075507 + ... + 1571075520.

It is an arithmetic number, because the mean of its divisors is an integer number (6284302056).

Almost surely, 2^21995057189 is an apocalyptic number.

It is an amenable number.

21995057189 is a deficient number, since it is larger than the sum of its proper divisors (3142151035).

21995057189 is an equidigital number, since it uses as much as digits as its factorization.

21995057189 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3142151034.

The product of its (nonzero) digits is 2041200, while the sum is 56.

The spelling of 21995057189 in words is "twenty-one billion, nine hundred ninety-five million, fifty-seven thousand, one hundred eighty-nine".