20997238080 has 224 divisors, whose sum is σ = 82051087104. Its totient is φ = 4430168064.

The previous prime is 20997238079. The next prime is 20997238099. The reversal of 20997238080 is 8083279902.

It is a happy number.

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

It is a Smith number, since the sum of its digits (48) coincides with the sum of the digits of its prime factors.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 32817 + ... + 207536.

It is an arithmetic number, because the mean of its divisors is an integer number (366299496).

Almost surely, 2^20997238080 is an apocalyptic number.

20997238080 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 20997238080, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (41025543552).

20997238080 is an abundant number, since it is smaller than the sum of its proper divisors (61053849024).

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

20997238080 is a wasteful number, since it uses less digits than its factorization.

20997238080 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 240393 (or 240383 counting only the distinct ones).

The product of its (nonzero) digits is 435456, while the sum is 48.

The spelling of 20997238080 in words is "twenty billion, nine hundred ninety-seven million, two hundred thirty-eight thousand, eighty".