21399211584 has 224 divisors, whose sum is σ = 67460774400. Its totient is φ = 6627778560.

The previous prime is 21399211579. The next prime is 21399211597. The reversal of 21399211584 is 48511299312.

21399211584 is a `hidden beast` number, since 21 + 39 + 9 + 2 + 11 + 584 = 666.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2316094 + ... + 2325314.

Almost surely, 2^21399211584 is an apocalyptic number.

21399211584 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21399211584, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33730387200).

21399211584 is an abundant number, since it is smaller than the sum of its proper divisors (46061562816).

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

21399211584 is a wasteful number, since it uses less digits than its factorization.

21399211584 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9338 (or 9322 counting only the distinct ones).

The product of its digits is 155520, while the sum is 45.

The spelling of 21399211584 in words is "twenty-one billion, three hundred ninety-nine million, two hundred eleven thousand, five hundred eighty-four".