665367551 has 2 divisors, whose sum is σ = 665367552. Its totient is φ = 665367550.

The previous prime is 665367541. The next prime is 665367569. The reversal of 665367551 is 155763566.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 665367551 - 2⁶ = 665367487 is a prime.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (665367541) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332683775 + 332683776.

It is an arithmetic number, because the mean of its divisors is an integer number (332683776).

Almost surely, 2^665367551 is an apocalyptic number.

665367551 is a deficient number, since it is larger than the sum of its proper divisors (1).

665367551 is an equidigital number, since it uses as much as digits as its factorization.

665367551 is an evil number, because the sum of its binary digits is even.

The product of its digits is 567000, while the sum is 44.

The square root of 665367551 is about 25794.7194402265. The cubic root of 665367551 is about 873.0126547171.

The spelling of 665367551 in words is "six hundred sixty-five million, three hundred sixty-seven thousand, five hundred fifty-one".