691861201 has 2 divisors, whose sum is σ = 691861202. Its totient is φ = 691861200.

The previous prime is 691861151. The next prime is 691861243. The reversal of 691861201 is 102168196.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 660490000 + 31371201 = 25700^2 + 5601^2 .

It is a cyclic number.

It is not a de Polignac number, because 691861201 - 2⁷ = 691861073 is a prime.

It is not a weakly prime, because it can be changed into another prime (691861301) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 345930600 + 345930601.

It is an arithmetic number, because the mean of its divisors is an integer number (345930601).

Almost surely, 2^691861201 is an apocalyptic number.

It is an amenable number.

691861201 is a deficient number, since it is larger than the sum of its proper divisors (1).

691861201 is an equidigital number, since it uses as much as digits as its factorization.

691861201 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5184, while the sum is 34.

The square root of 691861201 is about 26303.2545704899. The cubic root of 691861201 is about 884.4494009934.

The spelling of 691861201 in words is "six hundred ninety-one million, eight hundred sixty-one thousand, two hundred one".