691151597 has 2 divisors, whose sum is σ = 691151598. Its totient is φ = 691151596.

The previous prime is 691151579. The next prime is 691151621. The reversal of 691151597 is 795151196.

Together with previous prime (691151579) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 649536196 + 41615401 = 25486^2 + 6451^2 .

It is a cyclic number.

It is not a de Polignac number, because 691151597 - 2¹⁰ = 691150573 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (691150597) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 345575798 + 345575799.

It is an arithmetic number, because the mean of its divisors is an integer number (345575799).

Almost surely, 2^691151597 is an apocalyptic number.

It is an amenable number.

691151597 is a deficient number, since it is larger than the sum of its proper divisors (1).

691151597 is an equidigital number, since it uses as much as digits as its factorization.

691151597 is an evil number, because the sum of its binary digits is even.

The product of its digits is 85050, while the sum is 44.

The square root of 691151597 is about 26289.7622088904. The cubic root of 691151597 is about 884.1469205141.

The spelling of 691151597 in words is "six hundred ninety-one million, one hundred fifty-one thousand, five hundred ninety-seven".