691154957 has 2 divisors, whose sum is σ = 691154958. Its totient is φ = 691154956.

The previous prime is 691154921. The next prime is 691154987. The reversal of 691154957 is 759451196.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 449694436 + 241460521 = 21206^2 + 15539^2 .

It is a cyclic number.

It is not a de Polignac number, because 691154957 - 2²⁴ = 674377741 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (691154987) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 345577478 + 345577479.

It is an arithmetic number, because the mean of its divisors is an integer number (345577479).

Almost surely, 2^691154957 is an apocalyptic number.

It is an amenable number.

691154957 is a deficient number, since it is larger than the sum of its proper divisors (1).

691154957 is an equidigital number, since it uses as much as digits as its factorization.

691154957 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 340200, while the sum is 47.

The square root of 691154957 is about 26289.8261120153. The cubic root of 691154957 is about 884.1483532575.

The spelling of 691154957 in words is "six hundred ninety-one million, one hundred fifty-four thousand, nine hundred fifty-seven".