21195170208 has 360 divisors, whose sum is σ = 65886137856. Its totient is φ = 6682072320.

The previous prime is 21195170203. The next prime is 21195170233. The reversal of 21195170208 is 80207159112.

It is a happy number.

21195170208 is a `hidden beast` number, since 2 + 119 + 517 + 0 + 20 + 8 = 666.

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

It is not an unprimeable number, because it can be changed into a prime (21195170203) by changing a digit.

It is a polite number, since it can be written in 59 ways as a sum of consecutive naturals, for example, 166891041 + ... + 166891167.

Almost surely, 2^21195170208 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21195170208, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32943068928).

21195170208 is an abundant number, since it is smaller than the sum of its proper divisors (44690967648).

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

21195170208 is a wasteful number, since it uses less digits than its factorization.

21195170208 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 278 (or 230 counting only the distinct ones).

The product of its (nonzero) digits is 10080, while the sum is 36.

The spelling of 21195170208 in words is "twenty-one billion, one hundred ninety-five million, one hundred seventy thousand, two hundred eight".