691151 has 2 divisors, whose sum is σ = 691152. Its totient is φ = 691150.

The previous prime is 691147. The next prime is 691153. The reversal of 691151 is 151196.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 691151 - 2² = 691147 is a prime.

Together with 691153, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (691153) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 345575 + 345576.

It is an arithmetic number, because the mean of its divisors is an integer number (345576).

2⁶⁹¹¹⁵¹ is an apocalyptic number.

691151 is a deficient number, since it is larger than the sum of its proper divisors (1).

691151 is an equidigital number, since it uses as much as digits as its factorization.

691151 is an evil number, because the sum of its binary digits is even.

The product of its digits is 270, while the sum is 23.

The square root of 691151 is about 831.3549181908. The cubic root of 691151 is about 88.4146665946.

The spelling of 691151 in words is "six hundred ninety-one thousand, one hundred fifty-one".