20997173600 has 144 divisors (see below), whose sum is σ = 58108312080. Its totient is φ = 7344691200.

The previous prime is 20997173551. The next prime is 20997173627. The reversal of 20997173600 is 637179902.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 144470 + ... + 250730.

It is an arithmetic number, because the mean of its divisors is an integer number (403529945).

Almost surely, 2^20997173600 is an apocalyptic number.

20997173600 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 20997173600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29054156040).

20997173600 is an abundant number, since it is smaller than the sum of its proper divisors (37111138480).

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

20997173600 is a wasteful number, since it uses less digits than its factorization.

20997173600 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 106313 (or 106300 counting only the distinct ones).

The product of its (nonzero) digits is 142884, while the sum is 44.

The spelling of 20997173600 in words is "twenty billion, nine hundred ninety-seven million, one hundred seventy-three thousand, six hundred".