665620623361 has 2 divisors, whose sum is σ = 665620623362. Its totient is φ = 665620623360.

The previous prime is 665620623359. The next prime is 665620623407. The reversal of 665620623361 is 163326026566.

It is an a-pointer prime, because the next prime (665620623407) can be obtained adding 665620623361 to its sum of digits (46).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 424004136336 + 241616487025 = 651156^2 + 491545^2 .

It is a cyclic number.

It is not a de Polignac number, because 665620623361 - 2¹ = 665620623359 is a prime.

Together with 665620623359, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (665620623761) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332810311680 + 332810311681.

It is an arithmetic number, because the mean of its divisors is an integer number (332810311681).

Almost surely, 2^665620623361 is an apocalyptic number.

It is an amenable number.

665620623361 is a deficient number, since it is larger than the sum of its proper divisors (1).

665620623361 is an equidigital number, since it uses as much as digits as its factorization.

665620623361 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1399680, while the sum is 46.

The spelling of 665620623361 in words is "six hundred sixty-five billion, six hundred twenty million, six hundred twenty-three thousand, three hundred sixty-one".