663957893 has 2 divisors, whose sum is σ = 663957894. Its totient is φ = 663957892.

The previous prime is 663957881. The next prime is 663957901. The reversal of 663957893 is 398759366.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 661878529 + 2079364 = 25727^2 + 1442^2 .

It is a cyclic number.

It is not a de Polignac number, because 663957893 - 2²² = 659763589 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (663957293) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 331978946 + 331978947.

It is an arithmetic number, because the mean of its divisors is an integer number (331978947).

Almost surely, 2^663957893 is an apocalyptic number.

It is an amenable number.

663957893 is a deficient number, since it is larger than the sum of its proper divisors (1).

663957893 is an equidigital number, since it uses as much as digits as its factorization.

663957893 is an evil number, because the sum of its binary digits is even.

The product of its digits is 7348320, while the sum is 56.

The square root of 663957893 is about 25767.3804062423. The cubic root of 663957893 is about 872.3956927656.

The spelling of 663957893 in words is "six hundred sixty-three million, nine hundred fifty-seven thousand, eight hundred ninety-three".