21768193536 has 160 divisors (see below), whose sum is σ = 59519940480. Its totient is φ = 7067418624.

The previous prime is 21768193501. The next prime is 21768193567. The reversal of 21768193536 is 63539186712.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9305455 + ... + 9307793.

It is an arithmetic number, because the mean of its divisors is an integer number (371999628).

Almost surely, 2^21768193536 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21768193536, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29759970240).

21768193536 is an abundant number, since it is smaller than the sum of its proper divisors (37751746944).

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

21768193536 is an equidigital number, since it uses as much as digits as its factorization.

21768193536 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2516 (or 2500 counting only the distinct ones).

The product of its digits is 1632960, while the sum is 51.

The spelling of 21768193536 in words is "twenty-one billion, seven hundred sixty-eight million, one hundred ninety-three thousand, five hundred thirty-six".