665744637 has 8 divisors (see below), whose sum is σ = 926253504. Its totient is φ = 424532768.

The previous prime is 665744627. The next prime is 665744647. The reversal of 665744637 is 736447566.

It is an interprime number because it is at equal distance from previous prime (665744627) and next prime (665744647).

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 665744637 - 2⁴ = 665744621 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (665744617) 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, 4824168 + ... + 4824305.

It is an arithmetic number, because the mean of its divisors is an integer number (115781688).

Almost surely, 2^665744637 is an apocalyptic number.

It is an amenable number.

665744637 is a deficient number, since it is larger than the sum of its proper divisors (260508867).

665744637 is a wasteful number, since it uses less digits than its factorization.

665744637 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9648499.

The product of its digits is 2540160, while the sum is 48.

The square root of 665744637 is about 25802.0277691502. The cubic root of 665744637 is about 873.1775453750.

The spelling of 665744637 in words is "six hundred sixty-five million, seven hundred forty-four thousand, six hundred thirty-seven".