655116021 has 12 divisors (see below), whose sum is σ = 1081461472. Its totient is φ = 374351976.

The previous prime is 655116013. The next prime is 655116023. The reversal of 655116021 is 120611556.

It is a happy number.

655116021 is a `hidden beast` number, since 6 + 5 + 51 + 1 + 602 + 1 = 666.

655116021 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 655116021 - 2³ = 655116013 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (655116023) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5199271 + ... + 5199396.

Almost surely, 2^655116021 is an apocalyptic number.

It is an amenable number.

655116021 is a deficient number, since it is larger than the sum of its proper divisors (426345451).

655116021 is a wasteful number, since it uses less digits than its factorization.

655116021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10398680 (or 10398677 counting only the distinct ones).

The product of its (nonzero) digits is 1800, while the sum is 27.

The square root of 655116021 is about 25595.2343415723. The cubic root of 655116021 is about 868.5058340722.

Adding to 655116021 its reverse (120611556), we get a palindrome (775727577).

The spelling of 655116021 in words is "six hundred fifty-five million, one hundred sixteen thousand, twenty-one".