663681237 has 4 divisors (see below), whose sum is σ = 884908320. Its totient is φ = 442454156.

The previous prime is 663681223. The next prime is 663681257. The reversal of 663681237 is 732186366.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 663681237 - 2²⁴ = 646904021 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (663681217) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 110613537 + ... + 110613542.

It is an arithmetic number, because the mean of its divisors is an integer number (221227080).

Almost surely, 2^663681237 is an apocalyptic number.

It is an amenable number.

663681237 is a deficient number, since it is larger than the sum of its proper divisors (221227083).

663681237 is a wasteful number, since it uses less digits than its factorization.

663681237 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 221227082.

The product of its digits is 217728, while the sum is 42.

The square root of 663681237 is about 25762.0115091970. The cubic root of 663681237 is about 872.2745068515.

The spelling of 663681237 in words is "six hundred sixty-three million, six hundred eighty-one thousand, two hundred thirty-seven".