691820164 has 24 divisors (see below), whose sum is σ = 1386419328. Its totient is φ = 295898880.

The previous prime is 691820161. The next prime is 691820167. The reversal of 691820164 is 461028196.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (691820161) and next prime (691820167).

It is not an unprimeable number, because it can be changed into a prime (691820161) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10477 + ... + 38644.

It is an arithmetic number, because the mean of its divisors is an integer number (57767472).

Almost surely, 2^691820164 is an apocalyptic number.

It is an amenable number.

691820164 is an abundant number, since it is smaller than the sum of its proper divisors (694599164).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

691820164 is a wasteful number, since it uses less digits than its factorization.

691820164 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 49635 (or 49633 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 37.

The square root of 691820164 is about 26302.4744843522. The cubic root of 691820164 is about 884.4319139272.

The spelling of 691820164 in words is "six hundred ninety-one million, eight hundred twenty thousand, one hundred sixty-four".