21928990440 has 256 divisors, whose sum is σ = 76082872320. Its totient is φ = 4952908800.

The previous prime is 21928990423. The next prime is 21928990453. The reversal of 21928990440 is 4409982912.

It is a super-2 number, since 2×21928990440² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21928990440.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 31282090 + ... + 31282790.

It is an arithmetic number, because the mean of its divisors is an integer number (297198720).

Almost surely, 2^21928990440 is an apocalyptic number.

21928990440 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 21928990440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38041436160).

21928990440 is an abundant number, since it is smaller than the sum of its proper divisors (54153881880).

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

21928990440 is a wasteful number, since it uses less digits than its factorization.

21928990440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1112 (or 1108 counting only the distinct ones).

The product of its (nonzero) digits is 373248, while the sum is 48.

The spelling of 21928990440 in words is "twenty-one billion, nine hundred twenty-eight million, nine hundred ninety thousand, four hundred forty".