663752861 has 4 divisors (see below), whose sum is σ = 670595772. Its totient is φ = 656909952.

The previous prime is 663752827. The next prime is 663752893. The reversal of 663752861 is 168257366.

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

It can be written as a sum of positive squares in 2 ways, for example, as 92256025 + 571496836 = 9605^2 + 23906^2 .

It is a cyclic number.

It is not a de Polignac number, because 663752861 - 2¹⁴ = 663736477 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (663752161) 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, 3421310 + ... + 3421503.

It is an arithmetic number, because the mean of its divisors is an integer number (167648943).

Almost surely, 2^663752861 is an apocalyptic number.

It is an amenable number.

663752861 is a deficient number, since it is larger than the sum of its proper divisors (6842911).

663752861 is an equidigital number, since it uses as much as digits as its factorization.

663752861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6842910.

The product of its digits is 362880, while the sum is 44.

The square root of 663752861 is about 25763.4015805367. The cubic root of 663752861 is about 872.3058841344.

The spelling of 663752861 in words is "six hundred sixty-three million, seven hundred fifty-two thousand, eight hundred sixty-one".