21964051648 has 168 divisors, whose sum is σ = 55875428000. Its totient is φ = 8556387840.

The previous prime is 21964051607. The next prime is 21964051651. The reversal of 21964051648 is 84615046912.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 21964051598 and 21964051607.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2652058 + ... + 2660326.

Almost surely, 2^21964051648 is an apocalyptic number.

21964051648 is a gapful number since it is divisible by the number (28) 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 21964051648, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27937714000).

21964051648 is an abundant number, since it is smaller than the sum of its proper divisors (33911376352).

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

21964051648 is an equidigital number, since it uses as much as digits as its factorization.

21964051648 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8324 (or 8289 counting only the distinct ones).

The product of its (nonzero) digits is 414720, while the sum is 46.

The spelling of 21964051648 in words is "twenty-one billion, nine hundred sixty-four million, fifty-one thousand, six hundred forty-eight".