691506271 has 2 divisors, whose sum is σ = 691506272. Its totient is φ = 691506270.

The previous prime is 691506223. The next prime is 691506281. The reversal of 691506271 is 172605196.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 691506271 - 2²³ = 683117663 is a prime.

It is a super-3 number, since 3×691506271³ (a number of 27 digits) contains 333 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 691506271.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (691506281) 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, 345753135 + 345753136.

It is an arithmetic number, because the mean of its divisors is an integer number (345753136).

Almost surely, 2^691506271 is an apocalyptic number.

691506271 is a deficient number, since it is larger than the sum of its proper divisors (1).

691506271 is an equidigital number, since it uses as much as digits as its factorization.

691506271 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 22680, while the sum is 37.

The square root of 691506271 is about 26296.5068212491. The cubic root of 691506271 is about 884.2981320580.

The spelling of 691506271 in words is "six hundred ninety-one million, five hundred six thousand, two hundred seventy-one".