663417921 has 8 divisors (see below), whose sum is σ = 895214880. Its totient is φ = 436949792.

The previous prime is 663417893. The next prime is 663417959. The reversal of 663417921 is 129714366.

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

It is a cyclic number.

It is not a de Polignac number, because 663417921 - 2⁹ = 663417409 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 663417921.

It is not an unprimeable number, because it can be changed into a prime (663417961) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1331916 + ... + 1332413.

It is an arithmetic number, because the mean of its divisors is an integer number (111901860).

Almost surely, 2^663417921 is an apocalyptic number.

It is an amenable number.

663417921 is a deficient number, since it is larger than the sum of its proper divisors (231796959).

663417921 is a wasteful number, since it uses less digits than its factorization.

663417921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2664415.

The product of its digits is 54432, while the sum is 39.

The square root of 663417921 is about 25756.9004540531. The cubic root of 663417921 is about 872.1591330828.

The spelling of 663417921 in words is "six hundred sixty-three million, four hundred seventeen thousand, nine hundred twenty-one".