663437641 has 4 divisors (see below), whose sum is σ = 663490000. Its totient is φ = 663385284.

The previous prime is 663437609. The next prime is 663437681. The reversal of 663437641 is 146734366.

It is a happy number.

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, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 146734366 = 2 ⋅73367183.

It is a cyclic number.

It is not a de Polignac number, because 663437641 - 2⁵ = 663437609 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 663437594 and 663437603.

It is not an unprimeable number, because it can be changed into a prime (663437681) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6070 + ... + 36928.

It is an arithmetic number, because the mean of its divisors is an integer number (165872500).

Almost surely, 2^663437641 is an apocalyptic number.

It is an amenable number.

663437641 is a deficient number, since it is larger than the sum of its proper divisors (52359).

663437641 is a wasteful number, since it uses less digits than its factorization.

663437641 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 52358.

The product of its digits is 217728, while the sum is 40.

The square root of 663437641 is about 25757.2832612448. The cubic root of 663437641 is about 872.1677745978.

It can be divided in two parts, 66343 and 7641, that added together give a square (73984 = 272²).

The spelling of 663437641 in words is "six hundred sixty-three million, four hundred thirty-seven thousand, six hundred forty-one".