655865981 has 8 divisors (see below), whose sum is σ = 659197440. Its totient is φ = 652541392.

The previous prime is 655865963. The next prime is 655866011. The reversal of 655865981 is 189568556.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-655865981 is a prime.

It is a super-2 number, since 2×655865981² = 860320370066184722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (655865081) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 377591 + ... + 379323.

It is an arithmetic number, because the mean of its divisors is an integer number (82399680).

Almost surely, 2^655865981 is an apocalyptic number.

It is an amenable number.

655865981 is a deficient number, since it is larger than the sum of its proper divisors (3331459).

655865981 is a wasteful number, since it uses less digits than its factorization.

655865981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3435.

The product of its digits is 2592000, while the sum is 53.

The square root of 655865981 is about 25609.8805346686. The cubic root of 655865981 is about 868.8371220807.

The spelling of 655865981 in words is "six hundred fifty-five million, eight hundred sixty-five thousand, nine hundred eighty-one".