655677989 has 4 divisors (see below), whose sum is σ = 656814924. Its totient is φ = 654541056.

The previous prime is 655677977. The next prime is 655677991. The reversal of 655677989 is 989776556.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 654489889 + 1188100 = 25583^2 + 1090^2 .

It is a cyclic number.

It is not a de Polignac number, because 655677989 - 2¹⁶ = 655612453 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (655677929) 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, 567602 + ... + 568755.

It is an arithmetic number, because the mean of its divisors is an integer number (164203731).

Almost surely, 2^655677989 is an apocalyptic number.

It is an amenable number.

655677989 is a deficient number, since it is larger than the sum of its proper divisors (1136935).

655677989 is a wasteful number, since it uses less digits than its factorization.

655677989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1136934.

The product of its digits is 28576800, while the sum is 62.

The square root of 655677989 is about 25606.2099694586. The cubic root of 655677989 is about 868.7541020526.

The spelling of 655677989 in words is "six hundred fifty-five million, six hundred seventy-seven thousand, nine hundred eighty-nine".