691427026 has 8 divisors (see below), whose sum is σ = 1098148860. Its totient is φ = 325377408.

The previous prime is 691427017. The next prime is 691427047. The reversal of 691427026 is 620724196.

691427026 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Cunningham number, because it is equal to 26295²+1.

It can be written as a sum of positive squares in 2 ways, for example, as 691427025 + 1 = 26295^2 + 1^2 .

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

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10168011 + ... + 10168078.

Almost surely, 2^691427026 is an apocalyptic number.

691427026 is a deficient number, since it is larger than the sum of its proper divisors (406721834).

691427026 is a wasteful number, since it uses less digits than its factorization.

691427026 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20336108.

The product of its (nonzero) digits is 36288, while the sum is 37.

The square root of 691427026 is about 26295.0000190150. Note that the first 4 decimals coincide. The cubic root of 691427026 is about 884.2643512689.

The spelling of 691427026 in words is "six hundred ninety-one million, four hundred twenty-seven thousand, twenty-six".