20981897600 has 288 divisors, whose sum is σ = 56164139640. Its totient is φ = 7739596800.

The previous prime is 20981897551. The next prime is 20981897647. The reversal of 20981897600 is 679818902.

It is a Harshad number since it is a multiple of its sum of digits (50).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 47362979 + ... + 47363421.

Almost surely, 2^20981897600 is an apocalyptic number.

20981897600 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 20981897600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28082069820).

20981897600 is an abundant number, since it is smaller than the sum of its proper divisors (35182242040).

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

20981897600 is a wasteful number, since it uses less digits than its factorization.

20981897600 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 546 (or 510 counting only the distinct ones).

The product of its (nonzero) digits is 435456, while the sum is 50.

The spelling of 20981897600 in words is "twenty billion, nine hundred eighty-one million, eight hundred ninety-seven thousand, six hundred".