21797739900 has 360 divisors, whose sum is σ = 74531229696. Its totient is φ = 5502556800.

The previous prime is 21797739877. The next prime is 21797739919. The reversal of 21797739900 is 993779712.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 119 ways as a sum of consecutive naturals, for example, 11800777 + ... + 11802623.

Almost surely, 2^21797739900 is an apocalyptic number.

21797739900 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 21797739900, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37265614848).

21797739900 is an abundant number, since it is smaller than the sum of its proper divisors (52733489796).

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

21797739900 is a wasteful number, since it uses less digits than its factorization.

21797739900 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1951 (or 1935 counting only the distinct ones).

The product of its (nonzero) digits is 1500282, while the sum is 54.

The spelling of 21797739900 in words is "twenty-one billion, seven hundred ninety-seven million, seven hundred thirty-nine thousand, nine hundred".