665620273 has 2 divisors, whose sum is σ = 665620274. Its totient is φ = 665620272.

The previous prime is 665620229. The next prime is 665620279. The reversal of 665620273 is 372026566.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 357512464 + 308107809 = 18908^2 + 17553^2 .

It is a cyclic number.

It is not a de Polignac number, because 665620273 - 2²¹ = 663523121 is a prime.

It is equal to p_34562926 and since 665620273 and 34562926 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (665620279) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332810136 + 332810137.

It is an arithmetic number, because the mean of its divisors is an integer number (332810137).

Almost surely, 2^665620273 is an apocalyptic number.

It is an amenable number.

665620273 is a deficient number, since it is larger than the sum of its proper divisors (1).

665620273 is an equidigital number, since it uses as much as digits as its factorization.

665620273 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 90720, while the sum is 37.

The square root of 665620273 is about 25799.6176909659. The cubic root of 665620273 is about 873.1231708653.

The spelling of 665620273 in words is "six hundred sixty-five million, six hundred twenty thousand, two hundred seventy-three".