90805663885997 has 2 divisors, whose sum is σ = 90805663885998. Its totient is φ = 90805663885996.

The previous prime is 90805663885949. The next prime is 90805663886011. The reversal of 90805663885997 is 79958836650809.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 54117518444521 + 36688145441476 = 7356461^2 + 6057074^2 .

It is a cyclic number.

It is not a de Polignac number, because 90805663885997 - 2¹⁶ = 90805663820461 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (90805663885897) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45402831942998 + 45402831942999.

It is an arithmetic number, because the mean of its divisors is an integer number (45402831942999).

Almost surely, 2^{90805663885997} is an apocalyptic number.

It is an amenable number.

90805663885997 is a deficient number, since it is larger than the sum of its proper divisors (1).

90805663885997 is an equidigital number, since it uses as much as digits as its factorization.

90805663885997 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 7054387200, while the sum is 83.

The spelling of 90805663885997 in words is "ninety trillion, eight hundred five billion, six hundred sixty-three million, eight hundred eighty-five thousand, nine hundred ninety-seven".