21965598144 has 560 divisors, whose sum is σ = 77750627328. Its totient is φ = 6026462208.

The previous prime is 21965598133. The next prime is 21965598169. The reversal of 21965598144 is 44189556912.

21965598144 is a `hidden beast` number, since 2 + 1 + 9 + 6 + 5 + 598 + 1 + 44 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 414445222 + ... + 414445274.

Almost surely, 2^21965598144 is an apocalyptic number.

21965598144 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 21965598144, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38875313664).

21965598144 is an abundant number, since it is smaller than the sum of its proper divisors (55785029184).

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

21965598144 is an frugal number, since it uses more digits than its factorization.

21965598144 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 146 (or 112 counting only the distinct ones).

The product of its digits is 3110400, while the sum is 54.

The spelling of 21965598144 in words is "twenty-one billion, nine hundred sixty-five million, five hundred ninety-eight thousand, one hundred forty-four".