665550553 has 2 divisors, whose sum is σ = 665550554. Its totient is φ = 665550552.

The previous prime is 665550541. The next prime is 665550559. The reversal of 665550553 is 355055566.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 568488649 + 97061904 = 23843^2 + 9852^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-665550553 is a prime.

It is not a weakly prime, because it can be changed into another prime (665550559) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332775276 + 332775277.

It is an arithmetic number, because the mean of its divisors is an integer number (332775277).

Almost surely, 2^665550553 is an apocalyptic number.

It is an amenable number.

665550553 is a deficient number, since it is larger than the sum of its proper divisors (1).

665550553 is an equidigital number, since it uses as much as digits as its factorization.

665550553 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 337500, while the sum is 40.

The square root of 665550553 is about 25798.2664727691. The cubic root of 665550553 is about 873.0926848782.

The spelling of 665550553 in words is "six hundred sixty-five million, five hundred fifty thousand, five hundred fifty-three".