21397170600 has 768 divisors, whose sum is σ = 83019686400. Its totient is φ = 5094835200.

The previous prime is 21397170589. The next prime is 21397170623. The reversal of 21397170600 is 607179312.

It is a happy number.

21397170600 is a `hidden beast` number, since 2 + 1 + 39 + 7 + 17 + 0 + 600 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 301368565 + ... + 301368635.

It is an arithmetic number, because the mean of its divisors is an integer number (108098550).

Almost surely, 2^21397170600 is an apocalyptic number.

21397170600 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 21397170600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (41509843200).

21397170600 is an abundant number, since it is smaller than the sum of its proper divisors (61622515800).

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

21397170600 is a wasteful number, since it uses less digits than its factorization.

21397170600 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 174 (or 147 counting only the distinct ones).

The product of its (nonzero) digits is 15876, while the sum is 36.

The spelling of 21397170600 in words is "twenty-one billion, three hundred ninety-seven million, one hundred seventy thousand, six hundred".