665364551 has 2 divisors, whose sum is σ = 665364552. Its totient is φ = 665364550.

The previous prime is 665364529. The next prime is 665364577. The reversal of 665364551 is 155463566.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-665364551 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 665364499 and 665364508.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (665364521) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332682275 + 332682276.

It is an arithmetic number, because the mean of its divisors is an integer number (332682276).

Almost surely, 2^665364551 is an apocalyptic number.

665364551 is a deficient number, since it is larger than the sum of its proper divisors (1).

665364551 is an equidigital number, since it uses as much as digits as its factorization.

665364551 is an evil number, because the sum of its binary digits is even.

The product of its digits is 324000, while the sum is 41.

The square root of 665364551 is about 25794.6612887241. The cubic root of 665364551 is about 873.0113426393.

The spelling of 665364551 in words is "six hundred sixty-five million, three hundred sixty-four thousand, five hundred fifty-one".