816664687653 has 16 divisors (see below), whose sum is σ = 1108275125760. Its totient is φ = 534764240496.

The previous prime is 816664687649. The next prime is 816664687661. The reversal of 816664687653 is 356786466618.

It is not a de Polignac number, because 816664687653 - 2² = 816664687649 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (816664687253) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1733425 + ... + 2153622.

It is an arithmetic number, because the mean of its divisors is an integer number (69267195360).

Almost surely, 2^816664687653 is an apocalyptic number.

It is an amenable number.

816664687653 is a deficient number, since it is larger than the sum of its proper divisors (291610438107).

816664687653 is a wasteful number, since it uses less digits than its factorization.

816664687653 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3888296.

The product of its digits is 209018880, while the sum is 66.

The spelling of 816664687653 in words is "eight hundred sixteen billion, six hundred sixty-four million, six hundred eighty-seven thousand, six hundred fifty-three".