21904077888 has 224 divisors, whose sum is σ = 80283832320. Its totient is φ = 5689336320.

The previous prime is 21904077883. The next prime is 21904077889. The reversal of 21904077888 is 88877040912.

It is a happy number.

21904077888 is a `hidden beast` number, since 2 + 1 + 90 + 407 + 78 + 88 = 666.

It is a tau number, because it is divible by the number of its divisors (224).

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

It is not an unprimeable number, because it can be changed into a prime (21904077883) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 50745 + ... + 215367.

Almost surely, 2^21904077888 is an apocalyptic number.

21904077888 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 21904077888, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40141916160).

21904077888 is an abundant number, since it is smaller than the sum of its proper divisors (58379754432).

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

21904077888 is a wasteful number, since it uses less digits than its factorization.

21904077888 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 164662 (or 164646 counting only the distinct ones).

The product of its (nonzero) digits is 1806336, while the sum is 54.

The spelling of 21904077888 in words is "twenty-one billion, nine hundred four million, seventy-seven thousand, eight hundred eighty-eight".