21544142544 has 60 divisors (see below), whose sum is σ = 60334985412. Its totient is φ = 7176460800.

The previous prime is 21544142539. The next prime is 21544142549. The reversal of 21544142544 is 44524144512.

21544142544 is a `hidden beast` number, since 2 + 154 + 41 + 425 + 44 = 666.

It is an interprime number because it is at equal distance from previous prime (21544142539) and next prime (21544142549).

It can be written as a sum of positive squares in 2 ways, for example, as 3319142544 + 18225000000 = 57612^2 + 135000^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 21544142499 and 21544142508.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21544142549) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 162754 + ... + 263774.

Almost surely, 2^21544142544 is an apocalyptic number.

21544142544 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21544142544 is an abundant number, since it is smaller than the sum of its proper divisors (38790842868).

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

21544142544 is a wasteful number, since it uses less digits than its factorization.

21544142544 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 102516 (or 102507 counting only the distinct ones).

The product of its digits is 102400, while the sum is 36.

The spelling of 21544142544 in words is "twenty-one billion, five hundred forty-four million, one hundred forty-two thousand, five hundred forty-four".