21938735280 has 320 divisors, whose sum is σ = 89780825088. Its totient is φ = 4290478080.

The previous prime is 21938735257. The next prime is 21938735281. The reversal of 21938735280 is 8253783912.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is not an unprimeable number, because it can be changed into a prime (21938735281) 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, 279244 + ... + 349076.

Almost surely, 2^21938735280 is an apocalyptic number.

21938735280 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 21938735280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (44890412544).

21938735280 is an abundant number, since it is smaller than the sum of its proper divisors (67842089808).

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

21938735280 is a wasteful number, since it uses less digits than its factorization.

21938735280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 69884 (or 69878 counting only the distinct ones).

The product of its (nonzero) digits is 725760, while the sum is 48.

The spelling of 21938735280 in words is "twenty-one billion, nine hundred thirty-eight million, seven hundred thirty-five thousand, two hundred eighty".