21978552960 has 768 divisors, whose sum is σ = 96930812160. Its totient is φ = 4634247168.

The previous prime is 21978552941. The next prime is 21978552979. The reversal of 21978552960 is 6925587912.

21978552960 is a `hidden beast` number, since 2 + 19 + 78 + 552 + 9 + 6 + 0 = 666.

It is an interprime number because it is at equal distance from previous prime (21978552941) and next prime (21978552979).

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

It is a junction number, because it is equal to n+sod(n) for n = 21978552897 and 21978552906.

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, 14151544 + ... + 14153096.

It is an arithmetic number, because the mean of its divisors is an integer number (126211995).

Almost surely, 2^21978552960 is an apocalyptic number.

21978552960 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 21978552960, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (48465406080).

21978552960 is an abundant number, since it is smaller than the sum of its proper divisors (74952259200).

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

21978552960 is a wasteful number, since it uses less digits than its factorization.

21978552960 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1607 (or 1583 counting only the distinct ones).

The product of its (nonzero) digits is 2721600, while the sum is 54.

The spelling of 21978552960 in words is "twenty-one billion, nine hundred seventy-eight million, five hundred fifty-two thousand, nine hundred sixty".