691953903 has 6 divisors (see below), whose sum is σ = 999488984. Its totient is φ = 461302596.

The previous prime is 691953901. The next prime is 691953917. The reversal of 691953903 is 309359196.

It is not a de Polignac number, because 691953903 - 2¹ = 691953901 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (691953901) 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 in 5 ways as a sum of consecutive naturals, for example, 38441875 + ... + 38441892.

Almost surely, 2^691953903 is an apocalyptic number.

691953903 is a deficient number, since it is larger than the sum of its proper divisors (307535081).

691953903 is a wasteful number, since it uses less digits than its factorization.

691953903 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 76883773 (or 76883770 counting only the distinct ones).

The product of its (nonzero) digits is 196830, while the sum is 45.

The square root of 691953903 is about 26305.0166888371. The cubic root of 691953903 is about 884.4889014821.

The spelling of 691953903 in words is "six hundred ninety-one million, nine hundred fifty-three thousand, nine hundred three".