21426766768 has 60 divisors (see below), whose sum is σ = 45463538808. Its totient is φ = 9701908480.

The previous prime is 21426766741. The next prime is 21426766771. The reversal of 21426766768 is 86766762412.

It is a happy number.

It is a Smith number, since the sum of its digits (55) coincides with the sum of the digits of its prime factors.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 21930696 + ... + 21931672.

Almost surely, 2^21426766768 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 21426766768, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22731769404).

21426766768 is an abundant number, since it is smaller than the sum of its proper divisors (24036772040).

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

21426766768 is an equidigital number, since it uses as much as digits as its factorization.

21426766768 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1702 (or 1343 counting only the distinct ones).

The product of its digits is 8128512, while the sum is 55.

The spelling of 21426766768 in words is "twenty-one billion, four hundred twenty-six million, seven hundred sixty-six thousand, seven hundred sixty-eight".