21779079120 has 280 divisors, whose sum is σ = 77979420456. Its totient is φ = 5650228224.

The previous prime is 21779079089. The next prime is 21779079167. The reversal of 21779079120 is 2197097712.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 6029833104 + 15749246016 = 77652^2 + 125496^2 .

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 55 ways as a sum of consecutive naturals, for example, 2152794 + ... + 2162886.

Almost surely, 2^21779079120 is an apocalyptic number.

21779079120 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 21779079120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38989710228).

21779079120 is an abundant number, since it is smaller than the sum of its proper divisors (56200341336).

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

21779079120 is a wasteful number, since it uses less digits than its factorization.

21779079120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10161 (or 10140 counting only the distinct ones).

The product of its (nonzero) digits is 111132, while the sum is 45.

The spelling of 21779079120 in words is "twenty-one billion, seven hundred seventy-nine million, seventy-nine thousand, one hundred twenty".