691358953 has 2 divisors, whose sum is σ = 691358954. Its totient is φ = 691358952.

The previous prime is 691358951. The next prime is 691358963. The reversal of 691358953 is 359853196.

It is a happy number.

691358953 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 678706704 + 12652249 = 26052^2 + 3557^2 .

It is a cyclic number.

It is not a de Polignac number, because 691358953 - 2¹ = 691358951 is a prime.

Together with 691358951, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 691358897 and 691358906.

It is not a weakly prime, because it can be changed into another prime (691358951) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 345679476 + 345679477.

It is an arithmetic number, because the mean of its divisors is an integer number (345679477).

Almost surely, 2^691358953 is an apocalyptic number.

It is an amenable number.

691358953 is a deficient number, since it is larger than the sum of its proper divisors (1).

691358953 is an equidigital number, since it uses as much as digits as its factorization.

691358953 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 874800, while the sum is 49.

The square root of 691358953 is about 26293.7055775712. The cubic root of 691358953 is about 884.2353308515.

The spelling of 691358953 in words is "six hundred ninety-one million, three hundred fifty-eight thousand, nine hundred fifty-three".