813664653 has 4 divisors (see below), whose sum is σ = 1084886208. Its totient is φ = 542443100.

The previous prime is 813664651. The next prime is 813664667. The reversal of 813664653 is 356466318.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 813664653 - 2¹ = 813664651 is a prime.

It is a super-2 number, since 2×813664653² = 1324100335083220818, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (813664651) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 135610773 + ... + 135610778.

It is an arithmetic number, because the mean of its divisors is an integer number (271221552).

Almost surely, 2^813664653 is an apocalyptic number.

It is an amenable number.

813664653 is a deficient number, since it is larger than the sum of its proper divisors (271221555).

813664653 is a wasteful number, since it uses less digits than its factorization.

813664653 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 271221554.

The product of its digits is 311040, while the sum is 42.

The square root of 813664653 is about 28524.8076768276. The cubic root of 813664653 is about 933.5734307332.

The spelling of 813664653 in words is "eight hundred thirteen million, six hundred sixty-four thousand, six hundred fifty-three".