21442636824 has 64 divisors (see below), whose sum is σ = 61806896640. Its totient is φ = 6072245760.

The previous prime is 21442636819. The next prime is 21442636829. The reversal of 21442636824 is 42863624412.

It is an interprime number because it is at equal distance from previous prime (21442636819) and next prime (21442636829).

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21442636829) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 545772 + ... + 583739.

It is an arithmetic number, because the mean of its divisors is an integer number (965732760).

Almost surely, 2^21442636824 is an apocalyptic number.

21442636824 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21442636824 is an abundant number, since it is smaller than the sum of its proper divisors (40364259816).

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

21442636824 is a wasteful number, since it uses less digits than its factorization.

21442636824 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1129640 (or 1129636 counting only the distinct ones).

The product of its digits is 442368, while the sum is 42.

The spelling of 21442636824 in words is "twenty-one billion, four hundred forty-two million, six hundred thirty-six thousand, eight hundred twenty-four".