128274997 has 4 divisors (see below), whose sum is σ = 128475756. Its totient is φ = 128074240.

The previous prime is 128274973. The next prime is 128275039. The reversal of 128274997 is 799472821.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 113018161 + 15256836 = 10631^2 + 3906^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-128274997 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 128274997.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128274397) 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, 99418 + ... + 100699.

It is an arithmetic number, because the mean of its divisors is an integer number (32118939).

Almost surely, 2^128274997 is an apocalyptic number.

It is an amenable number.

128274997 is a deficient number, since it is larger than the sum of its proper divisors (200759).

128274997 is an equidigital number, since it uses as much as digits as its factorization.

128274997 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 200758.

The product of its digits is 508032, while the sum is 49.

The square root of 128274997 is about 11325.8552436450. The cubic root of 128274997 is about 504.3290727508.

The spelling of 128274997 in words is "one hundred twenty-eight million, two hundred seventy-four thousand, nine hundred ninety-seven".