21916978272 has 384 divisors, whose sum is σ = 78686899200. Its totient is φ = 5792145408.

The previous prime is 21916978261. The next prime is 21916978273. The reversal of 21916978272 is 27287961912.

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

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21916978273) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 6064338 + ... + 6067950.

It is an arithmetic number, because the mean of its divisors is an integer number (204913800).

Almost surely, 2^21916978272 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 21916978272, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39343449600).

21916978272 is an abundant number, since it is smaller than the sum of its proper divisors (56769920928).

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

21916978272 is a wasteful number, since it uses less digits than its factorization.

21916978272 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3715 (or 3701 counting only the distinct ones).

The product of its digits is 1524096, while the sum is 54.

The spelling of 21916978272 in words is "twenty-one billion, nine hundred sixteen million, nine hundred seventy-eight thousand, two hundred seventy-two".