21170250000 has 315 divisors, whose sum is σ = 74829530451. Its totient is φ = 5587200000.

The previous prime is 21170249869. The next prime is 21170250011. The reversal of 21170250000 is 5207112.

The square root of 21170250000 is 145500.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 10 ways, for example, as 16712284176 + 4457965824 = 129276^2 + 66768^2 .

It is a Harshad number since it is a multiple of its sum of digits (18).

It is an unprimeable number.

It is a polite number, since it can be written in 62 ways as a sum of consecutive naturals, for example, 218249952 + ... + 218250048.

Almost surely, 2^21170250000 is an apocalyptic number.

21170250000 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

21170250000 is the 145500-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21170250000

21170250000 is an abundant number, since it is smaller than the sum of its proper divisors (53659280451).

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

21170250000 is an frugal number, since it uses more digits than its factorization.

21170250000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 238 (or 107 counting only the distinct ones).

The product of its (nonzero) digits is 140, while the sum is 18.

Adding to 21170250000 its reverse (5207112), we get a palindrome (21175457112).

The spelling of 21170250000 in words is "twenty-one billion, one hundred seventy million, two hundred fifty thousand".