128380705 has 16 divisors (see below), whose sum is σ = 155952720. Its totient is φ = 101449728.

The previous prime is 128380673. The next prime is 128380711. The reversal of 128380705 is 507083821.

It can be written as a sum of positive squares in 8 ways, for example, as 57121 + 128323584 = 239^2 + 11328^2 .

It is a cyclic number.

It is not a de Polignac number, because 128380705 - 2⁵ = 128380673 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 166561 + ... + 167329.

It is an arithmetic number, because the mean of its divisors is an integer number (9747045).

Almost surely, 2^128380705 is an apocalyptic number.

It is an amenable number.

128380705 is a deficient number, since it is larger than the sum of its proper divisors (27572015).

128380705 is a wasteful number, since it uses less digits than its factorization.

128380705 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1140.

The product of its (nonzero) digits is 13440, while the sum is 34.

The square root of 128380705 is about 11330.5209500711. The cubic root of 128380705 is about 504.4675694216.

The spelling of 128380705 in words is "one hundred twenty-eight million, three hundred eighty thousand, seven hundred five".