664747943 has 4 divisors (see below), whose sum is σ = 664805328. Its totient is φ = 664690560.

The previous prime is 664747939. The next prime is 664747961. The reversal of 664747943 is 349747466.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 664747943 - 2² = 664747939 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 664747891 and 664747900.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (664747933) 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, 4538 + ... + 36743.

It is an arithmetic number, because the mean of its divisors is an integer number (166201332).

Almost surely, 2^664747943 is an apocalyptic number.

664747943 is a deficient number, since it is larger than the sum of its proper divisors (57385).

664747943 is a wasteful number, since it uses less digits than its factorization.

664747943 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 57384.

The product of its digits is 3048192, while the sum is 50.

The square root of 664747943 is about 25782.7062776583. The cubic root of 664747943 is about 872.7415796703.

The spelling of 664747943 in words is "six hundred sixty-four million, seven hundred forty-seven thousand, nine hundred forty-three".