115221720 has 128 divisors (see below), whose sum is σ = 364953600. Its totient is φ = 29044224.

The previous prime is 115221703. The next prime is 115221731. The reversal of 115221720 is 27122511.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 300649 + ... + 301031.

It is an arithmetic number, because the mean of its divisors is an integer number (2851200).

Almost surely, 2^115221720 is an apocalyptic number.

115221720 is a gapful number since it is divisible by the number (10) 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 115221720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (182476800).

115221720 is an abundant number, since it is smaller than the sum of its proper divisors (249731880).

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

115221720 is a wasteful number, since it uses less digits than its factorization.

115221720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 529 (or 525 counting only the distinct ones).

The product of its (nonzero) digits is 280, while the sum is 21.

The square root of 115221720 is about 10734.1380650707. The cubic root of 115221720 is about 486.6067376842.

The spelling of 115221720 in words is "one hundred fifteen million, two hundred twenty-one thousand, seven hundred twenty".