128699629 has 4 divisors (see below), whose sum is σ = 128837340. Its totient is φ = 128561920.

The previous prime is 128699609. The next prime is 128699671. The reversal of 128699629 is 926996821.

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 25270729 + 103428900 = 5027^2 + 10170^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-128699629 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128699609) 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, 67444 + ... + 69325.

It is an arithmetic number, because the mean of its divisors is an integer number (32209335).

Almost surely, 2^128699629 is an apocalyptic number.

It is an amenable number.

128699629 is a deficient number, since it is larger than the sum of its proper divisors (137711).

128699629 is an equidigital number, since it uses as much as digits as its factorization.

128699629 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 137710.

The product of its digits is 839808, while the sum is 52.

The square root of 128699629 is about 11344.5858893130. The cubic root of 128699629 is about 504.8849576197.

The spelling of 128699629 in words is "one hundred twenty-eight million, six hundred ninety-nine thousand, six hundred twenty-nine".