128820615 has 32 divisors (see below), whose sum is σ = 256974336. Its totient is φ = 53535360.

The previous prime is 128820607. The next prime is 128820619. The reversal of 128820615 is 516028821.

It is not a de Polignac number, because 128820615 - 2³ = 128820607 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128820619) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 54612 + ... + 56921.

It is an arithmetic number, because the mean of its divisors is an integer number (8030448).

Almost surely, 2^128820615 is an apocalyptic number.

128820615 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

128820615 is a deficient number, since it is larger than the sum of its proper divisors (128153721).

128820615 is a wasteful number, since it uses less digits than its factorization.

128820615 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 111559.

The product of its (nonzero) digits is 7680, while the sum is 33.

The square root of 128820615 is about 11349.9169600487. The cubic root of 128820615 is about 505.0431162742.

The spelling of 128820615 in words is "one hundred twenty-eight million, eight hundred twenty thousand, six hundred fifteen".