128684690 has 8 divisors (see below), whose sum is σ = 231632460. Its totient is φ = 51473872.

The previous prime is 128684669. The next prime is 128684693. The reversal of 128684690 is 96486821.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 123454321 + 5230369 = 11111^2 + 2287^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×128684690² = 33119498880792200, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (128684693) 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, 6434225 + ... + 6434244.

Almost surely, 2^128684690 is an apocalyptic number.

128684690 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

128684690 is a deficient number, since it is larger than the sum of its proper divisors (102947770).

128684690 is a wasteful number, since it uses less digits than its factorization.

128684690 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12868476.

The product of its (nonzero) digits is 165888, while the sum is 44.

The square root of 128684690 is about 11343.9274504027. The cubic root of 128684690 is about 504.8654217741.

The spelling of 128684690 in words is "one hundred twenty-eight million, six hundred eighty-four thousand, six hundred ninety".