655694921 has 16 divisors (see below), whose sum is σ = 804912000. Its totient is φ = 532438704.

The previous prime is 655694909. The next prime is 655694927. The reversal of 655694921 is 129496556.

It is not a de Polignac number, because 655694921 - 2¹⁰ = 655693897 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (655694927) 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 15 ways as a sum of consecutive naturals, for example, 43790 + ... + 56823.

It is an arithmetic number, because the mean of its divisors is an integer number (50307000).

Almost surely, 2^655694921 is an apocalyptic number.

It is an amenable number.

655694921 is a deficient number, since it is larger than the sum of its proper divisors (149217079).

655694921 is a wasteful number, since it uses less digits than its factorization.

655694921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 100653 (or 100639 counting only the distinct ones).

The product of its digits is 583200, while the sum is 47.

The square root of 655694921 is about 25606.5405902476. The cubic root of 655694921 is about 868.7615801227.

The spelling of 655694921 in words is "six hundred fifty-five million, six hundred ninety-four thousand, nine hundred twenty-one".