665020001291 has 2 divisors, whose sum is σ = 665020001292. Its totient is φ = 665020001290.

The previous prime is 665020001207. The next prime is 665020001309. The reversal of 665020001291 is 192100020566.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 665020001291 - 2²⁶ = 664952892427 is a prime.

It is not a weakly prime, because it can be changed into another prime (665020061291) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332510000645 + 332510000646.

It is an arithmetic number, because the mean of its divisors is an integer number (332510000646).

Almost surely, 2^665020001291 is an apocalyptic number.

665020001291 is a deficient number, since it is larger than the sum of its proper divisors (1).

665020001291 is an equidigital number, since it uses as much as digits as its factorization.

665020001291 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6480, while the sum is 32.

The spelling of 665020001291 in words is "six hundred sixty-five billion, twenty million, one thousand, two hundred ninety-one".