691362128 has 10 divisors (see below), whose sum is σ = 1339514154. Its totient is φ = 345681056.

The previous prime is 691362097. The next prime is 691362163. The reversal of 691362128 is 821263196.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 687068944 + 4293184 = 26212^2 + 2072^2 .

It is a junction number, because it is equal to n+sod(n) for n = 691362091 and 691362100.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21605051 + ... + 21605082.

Almost surely, 2^691362128 is an apocalyptic number.

It is an amenable number.

691362128 is a deficient number, since it is larger than the sum of its proper divisors (648152026).

691362128 is a wasteful number, since it uses less digits than its factorization.

691362128 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43210141 (or 43210135 counting only the distinct ones).

The product of its digits is 31104, while the sum is 38.

The square root of 691362128 is about 26293.7659531684. The cubic root of 691362128 is about 884.2366844382.

The spelling of 691362128 in words is "six hundred ninety-one million, three hundred sixty-two thousand, one hundred twenty-eight".