21424455144 has 48 divisors (see below), whose sum is σ = 58207670820. Its totient is φ = 7118949120.

The previous prime is 21424455131. The next prime is 21424455161. The reversal of 21424455144 is 44155442412.

21424455144 is a `hidden beast` number, since 21 + 4 + 2 + 44 + 551 + 44 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 19248232644 + 2176222500 = 138738^2 + 46650^2 .

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 = 21424455099 and 21424455108.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 446517 + ... + 492164.

Almost surely, 2^21424455144 is an apocalyptic number.

21424455144 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21424455144 is an abundant number, since it is smaller than the sum of its proper divisors (36783215676).

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

21424455144 is a wasteful number, since it uses less digits than its factorization.

21424455144 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 939010 (or 939003 counting only the distinct ones).

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

Adding to 21424455144 its reverse (44155442412), we get a palindrome (65579897556).

The spelling of 21424455144 in words is "twenty-one billion, four hundred twenty-four million, four hundred fifty-five thousand, one hundred forty-four".