663156943 has 4 divisors (see below), whose sum is σ = 698059960. Its totient is φ = 628253928.

The previous prime is 663156941. The next prime is 663156947. The reversal of 663156943 is 349651366.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 663156943 - 2¹ = 663156941 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 663156943.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (663156941) 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, 17451480 + ... + 17451517.

It is an arithmetic number, because the mean of its divisors is an integer number (174514990).

Almost surely, 2^663156943 is an apocalyptic number.

663156943 is a deficient number, since it is larger than the sum of its proper divisors (34903017).

663156943 is a wasteful number, since it uses less digits than its factorization.

663156943 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34903016.

The product of its digits is 349920, while the sum is 43.

The square root of 663156943 is about 25751.8337793641. The cubic root of 663156943 is about 872.0447535983.

The spelling of 663156943 in words is "six hundred sixty-three million, one hundred fifty-six thousand, nine hundred forty-three".