128739697 has 4 divisors (see below), whose sum is σ = 129393396. Its totient is φ = 128086000.

The previous prime is 128739647. The next prime is 128739701. The reversal of 128739697 is 796937821.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 796937821 = 173 ⋅4606577.

It can be written as a sum of positive squares in 2 ways, for example, as 125350416 + 3389281 = 11196^2 + 1841^2 .

It is a cyclic number.

It is not a de Polignac number, because 128739697 - 2²³ = 120351089 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (128739617) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 326554 + ... + 326947.

It is an arithmetic number, because the mean of its divisors is an integer number (32348349).

Almost surely, 2^128739697 is an apocalyptic number.

It is an amenable number.

128739697 is a deficient number, since it is larger than the sum of its proper divisors (653699).

128739697 is an equidigital number, since it uses as much as digits as its factorization.

128739697 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 653698.

The product of its digits is 1143072, while the sum is 52.

The square root of 128739697 is about 11346.3517044026. The cubic root of 128739697 is about 504.9373473886.

The spelling of 128739697 in words is "one hundred twenty-eight million, seven hundred thirty-nine thousand, six hundred ninety-seven".