21399593796 has 297 divisors, whose sum is σ = 66899806911. Its totient is φ = 5971979664.

The previous prime is 21399593791. The next prime is 21399593797. The reversal of 21399593796 is 69739599312.

The square root of 21399593796 is 146286.

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

21399593796 is a `hidden beast` number, since 2 + 1 + 39 + 9 + 593 + 7 + 9 + 6 = 666.

It is a super-2 number, since 2×21399593796² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is not an unprimeable number, because it can be changed into a prime (21399593791) by changing a digit.

It is a polite number, since it can be written in 98 ways as a sum of consecutive naturals, for example, 497664951 + ... + 497664993.

Almost surely, 2^21399593796 is an apocalyptic number.

21399593796 is the 146286-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21399593796

21399593796 is an abundant number, since it is smaller than the sum of its proper divisors (45500213115).

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

21399593796 is an frugal number, since it uses more digits than its factorization.

21399593796 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 134 (or 55 counting only the distinct ones).

The product of its digits is 24800580, while the sum is 63.

The spelling of 21399593796 in words is "twenty-one billion, three hundred ninety-nine million, five hundred ninety-three thousand, seven hundred ninety-six".