691499861 has 8 divisors (see below), whose sum is σ = 760537344. Its totient is φ = 624726000.

The previous prime is 691499849. The next prime is 691499869. The reversal of 691499861 is 168994196.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 691499861 - 2⁶ = 691499797 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 (691499869) 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 7 ways as a sum of consecutive naturals, for example, 565265 + ... + 566486.

It is an arithmetic number, because the mean of its divisors is an integer number (95067168).

Almost surely, 2^691499861 is an apocalyptic number.

It is an amenable number.

691499861 is a deficient number, since it is larger than the sum of its proper divisors (69037483).

691499861 is a wasteful number, since it uses less digits than its factorization.

691499861 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1131811.

The product of its digits is 839808, while the sum is 53.

The square root of 691499861 is about 26296.3849416607. The cubic root of 691499861 is about 884.2953996805.

The spelling of 691499861 in words is "six hundred ninety-one million, four hundred ninety-nine thousand, eight hundred sixty-one".