21444089172 has 48 divisors (see below), whose sum is σ = 56345769984. Its totient is φ = 6288588000.

The previous prime is 21444089159. The next prime is 21444089209. The reversal of 21444089172 is 27198044412.

It is a super-4 number, since 4×21444089172⁴ (a number of 42 digits) contains 4444 as substring.

It is a congruent number.

It is an unprimeable number.

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, 2616154 + ... + 2624337.

It is an arithmetic number, because the mean of its divisors is an integer number (1173870208).

Almost surely, 2^21444089172 is an apocalyptic number.

21444089172 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

21444089172 is an abundant number, since it is smaller than the sum of its proper divisors (34901680812).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21444089172 is a wasteful number, since it uses less digits than its factorization.

21444089172 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5240540 (or 5240538 counting only the distinct ones).

The product of its (nonzero) digits is 129024, while the sum is 42.

The spelling of 21444089172 in words is "twenty-one billion, four hundred forty-four million, eighty-nine thousand, one hundred seventy-two".