653666566 has 12 divisors (see below), whose sum is σ = 1140581628. Its totient is φ = 280142772.

The previous prime is 653666561. The next prime is 653666581. The reversal of 653666566 is 665666356.

It is a Harshad number since it is a multiple of its sum of digits (49).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (653666561) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 3334936 + ... + 3335131.

It is an arithmetic number, because the mean of its divisors is an integer number (95048469).

Almost surely, 2^653666566 is an apocalyptic number.

653666566 is a deficient number, since it is larger than the sum of its proper divisors (486915062).

653666566 is a wasteful number, since it uses less digits than its factorization.

653666566 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6670083 (or 6670076 counting only the distinct ones).

The product of its digits is 3499200, while the sum is 49.

The square root of 653666566 is about 25566.9037233686. The cubic root of 653666566 is about 867.8648332711.

The spelling of 653666566 in words is "six hundred fifty-three million, six hundred sixty-six thousand, five hundred sixty-six".