691602061 has 2 divisors, whose sum is σ = 691602062. Its totient is φ = 691602060.

The previous prime is 691602031. The next prime is 691602077. The reversal of 691602061 is 160206196.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 431392900 + 260209161 = 20770^2 + 16131^2 .

It is a cyclic number.

It is not a de Polignac number, because 691602061 - 2⁵ = 691602029 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (691602031) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 345801030 + 345801031.

It is an arithmetic number, because the mean of its divisors is an integer number (345801031).

Almost surely, 2^691602061 is an apocalyptic number.

It is an amenable number.

691602061 is a deficient number, since it is larger than the sum of its proper divisors (1).

691602061 is an equidigital number, since it uses as much as digits as its factorization.

691602061 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3888, while the sum is 31.

The square root of 691602061 is about 26298.3281027521. The cubic root of 691602061 is about 884.3389622527.

The spelling of 691602061 in words is "six hundred ninety-one million, six hundred two thousand, sixty-one".