690128 has 10 divisors (see below), whose sum is σ = 1337154. Its totient is φ = 345056.

The previous prime is 690127. The next prime is 690139. The reversal of 690128 is 821096.

It can be written as a sum of positive squares in only one way, i.e., 506944 + 183184 = 712^2 + 428^2 .

It is a junction number, because it is equal to n+sod(n) for n = 690097 and 690106.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (690127) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21551 + ... + 21582.

2⁶⁹⁰¹²⁸ is an apocalyptic number.

It is an amenable number.

690128 is a deficient number, since it is larger than the sum of its proper divisors (647026).

690128 is a wasteful number, since it uses less digits than its factorization.

690128 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43141 (or 43135 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 26.

The square root of 690128 is about 830.7394296649. The cubic root of 690128 is about 88.3710230367.

It can be divided in two parts, 690 and 128, that added together give a palindrome (818).

The spelling of 690128 in words is "six hundred ninety thousand, one hundred twenty-eight".