21362724864 has 468 divisors, whose sum is σ = 69839218176. Its totient is φ = 6521389056.

The previous prime is 21362724863. The next prime is 21362724937. The reversal of 21362724864 is 46842726312.

It is a happy number.

21362724864 is a `hidden beast` number, since 2 + 13 + 627 + 2 + 4 + 8 + 6 + 4 = 666.

It is a tau number, because it is divible by the number of its divisors (468).

It is a super-2 number, since 2×21362724864² (a number of 21 digits) contains 22 as substring.

Its product of digits (774144) is a multiple of the sum of its prime factors (192).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21362724863) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 168210369 + ... + 168210495.

Almost surely, 2^21362724864 is an apocalyptic number.

21362724864 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 21362724864, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34919609088).

21362724864 is an abundant number, since it is smaller than the sum of its proper divisors (48476493312).

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

21362724864 is an equidigital number, since it uses as much as digits as its factorization.

21362724864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 192 (or 145 counting only the distinct ones).

The product of its digits is 774144, while the sum is 45.

The spelling of 21362724864 in words is "twenty-one billion, three hundred sixty-two million, seven hundred twenty-four thousand, eight hundred sixty-four".