663991654 has 8 divisors (see below), whose sum is σ = 1017178848. Its totient is φ = 324932040.

The previous prime is 663991639. The next prime is 663991673. The reversal of 663991654 is 456199366.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a junction number, because it is equal to n+sod(n) for n = 663991598 and 663991607.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3531777 + ... + 3531964.

It is an arithmetic number, because the mean of its divisors is an integer number (127147356).

Almost surely, 2^663991654 is an apocalyptic number.

663991654 is a deficient number, since it is larger than the sum of its proper divisors (353187194).

663991654 is a wasteful number, since it uses less digits than its factorization.

663991654 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7063790.

The product of its digits is 1049760, while the sum is 49.

The square root of 663991654 is about 25768.0355091342. The cubic root of 663991654 is about 872.4104790707.

The spelling of 663991654 in words is "six hundred sixty-three million, nine hundred ninety-one thousand, six hundred fifty-four".