128690494 has 4 divisors (see below), whose sum is σ = 193035744. Its totient is φ = 64345246.

The previous prime is 128690491. The next prime is 128690501. The reversal of 128690494 is 494096821.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 494096821 = 4127 ⋅119723.

It is a super-2 number, since 2×128690494² = 33122486491928072, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 128690494.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128690491) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32172622 + ... + 32172625.

It is an arithmetic number, because the mean of its divisors is an integer number (48258936).

Almost surely, 2^128690494 is an apocalyptic number.

128690494 is a deficient number, since it is larger than the sum of its proper divisors (64345250).

128690494 is an equidigital number, since it uses as much as digits as its factorization.

128690494 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 64345249.

The product of its (nonzero) digits is 124416, while the sum is 43.

The square root of 128690494 is about 11344.1832672079. The cubic root of 128690494 is about 504.8730118893.

The spelling of 128690494 in words is "one hundred twenty-eight million, six hundred ninety thousand, four hundred ninety-four".