663671837 has 2 divisors, whose sum is σ = 663671838. Its totient is φ = 663671836.

The previous prime is 663671773. The next prime is 663671863. The reversal of 663671837 is 738176366.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 435389956 + 228281881 = 20866^2 + 15109^2 .

It is a cyclic number.

It is not a de Polignac number, because 663671837 - 2⁶ = 663671773 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 663671791 and 663671800.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (663671867) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 331835918 + 331835919.

It is an arithmetic number, because the mean of its divisors is an integer number (331835919).

Almost surely, 2^663671837 is an apocalyptic number.

It is an amenable number.

663671837 is a deficient number, since it is larger than the sum of its proper divisors (1).

663671837 is an equidigital number, since it uses as much as digits as its factorization.

663671837 is an evil number, because the sum of its binary digits is even.

The product of its digits is 762048, while the sum is 47.

The square root of 663671837 is about 25761.8290693809. The cubic root of 663671837 is about 872.2703887002.

The spelling of 663671837 in words is "six hundred sixty-three million, six hundred seventy-one thousand, eight hundred thirty-seven".