21977464320 has 960 divisors, whose sum is σ = 92944051200. Its totient is φ = 4974649344.

The previous prime is 21977464297. The next prime is 21977464337. The reversal of 21977464320 is 2346477912.

21977464320 is a `hidden beast` number, since 219 + 77 + 46 + 4 + 320 = 666.

It is a tau number, because it is divible by the number of its divisors (960).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 213373389 + ... + 213373491.

It is an arithmetic number, because the mean of its divisors is an integer number (96816720).

Almost surely, 2^21977464320 is an apocalyptic number.

21977464320 is a gapful number since it is divisible by the number (20) 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 21977464320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (46472025600).

21977464320 is an abundant number, since it is smaller than the sum of its proper divisors (70966586880).

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

21977464320 is an frugal number, since it uses more digits than its factorization.

21977464320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 162 (or 120 counting only the distinct ones).

The product of its (nonzero) digits is 508032, while the sum is 45.

The spelling of 21977464320 in words is "twenty-one billion, nine hundred seventy-seven million, four hundred sixty-four thousand, three hundred twenty".