128720215 has 32 divisors (see below), whose sum is σ = 173408256. Its totient is φ = 91082880.

The previous prime is 128720203. The next prime is 128720227. The reversal of 128720215 is 512027821.

It is an interprime number because it is at equal distance from previous prime (128720203) and next prime (128720227).

It is not a de Polignac number, because 128720215 - 2¹⁹ = 128195927 is a prime.

It is a Duffinian number.

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, 255654 + ... + 256156.

It is an arithmetic number, because the mean of its divisors is an integer number (5419008).

Almost surely, 2^128720215 is an apocalyptic number.

128720215 is a deficient number, since it is larger than the sum of its proper divisors (44688041).

128720215 is a wasteful number, since it uses less digits than its factorization.

128720215 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 679.

The product of its (nonzero) digits is 2240, while the sum is 28.

The square root of 128720215 is about 11345.4931580782. The cubic root of 128720215 is about 504.9118756139.

The spelling of 128720215 in words is "one hundred twenty-eight million, seven hundred twenty thousand, two hundred fifteen".