655855691 has 2 divisors, whose sum is σ = 655855692. Its totient is φ = 655855690.

The previous prime is 655855679. The next prime is 655855723. The reversal of 655855691 is 196558556.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-655855691 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (655855601) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 327927845 + 327927846.

It is an arithmetic number, because the mean of its divisors is an integer number (327927846).

Almost surely, 2^655855691 is an apocalyptic number.

655855691 is a deficient number, since it is larger than the sum of its proper divisors (1).

655855691 is an equidigital number, since it uses as much as digits as its factorization.

655855691 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1620000, while the sum is 50.

The square root of 655855691 is about 25609.6796348568. The cubic root of 655855691 is about 868.8325782760.

The spelling of 655855691 in words is "six hundred fifty-five million, eight hundred fifty-five thousand, six hundred ninety-one".