691861453 has 2 divisors, whose sum is σ = 691861454. Its totient is φ = 691861452.

The previous prime is 691861411. The next prime is 691861493. The reversal of 691861453 is 354168196.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 398321764 + 293539689 = 19958^2 + 17133^2 .

It is a cyclic number.

It is not a de Polignac number, because 691861453 - 2⁹ = 691860941 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (691861493) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 345930726 + 345930727.

It is an arithmetic number, because the mean of its divisors is an integer number (345930727).

Almost surely, 2^691861453 is an apocalyptic number.

It is an amenable number.

691861453 is a deficient number, since it is larger than the sum of its proper divisors (1).

691861453 is an equidigital number, since it uses as much as digits as its factorization.

691861453 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 155520, while the sum is 43.

The square root of 691861453 is about 26303.2593607712. The cubic root of 691861453 is about 884.4495083758.

The spelling of 691861453 in words is "six hundred ninety-one million, eight hundred sixty-one thousand, four hundred fifty-three".