21199283815824 has 135 divisors (see below), whose sum is σ = 60747179747787. Its totient is φ = 6901318888128.

The previous prime is 21199283815789. The next prime is 21199283815841. The reversal of 21199283815824 is 42851838299112.

The square root of 21199283815824 is 4604268.

It is a perfect power (a square), and thus also a powerful number.

21199283815824 is a `hidden beast` number, since 2 + 1 + 19 + 9 + 2 + 8 + 38 + 1 + 582 + 4 = 666.

It is an unprimeable number.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 2375797827 + ... + 2375806749.

Almost surely, 2^{21199283815824} is an apocalyptic number.

21199283815824 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

21199283815824 is the 4604268-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21199283815824

21199283815824 is an abundant number, since it is smaller than the sum of its proper divisors (39547895931963).

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

21199283815824 is an frugal number, since it uses more digits than its factorization.

21199283815824 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17946 (or 8971 counting only the distinct ones).

The product of its digits is 19906560, while the sum is 63.

The spelling of 21199283815824 in words is "twenty-one trillion, one hundred ninety-nine billion, two hundred eighty-three million, eight hundred fifteen thousand, eight hundred twenty-four".