665250450681 has 8 divisors (see below), whose sum is σ = 890273666944. Its totient is φ = 441863767440.

The previous prime is 665250450679. The next prime is 665250450703. The reversal of 665250450681 is 186054052566.

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

It is not a de Polignac number, because 665250450681 - 2¹ = 665250450679 is a prime.

It is a super-2 number, since 2×665250450681² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

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 665250450681.

It is not an unprimeable number, because it can be changed into a prime (665250450611) 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, 409132306 + ... + 409133931.

It is an arithmetic number, because the mean of its divisors is an integer number (111284208368).

Almost surely, 2^665250450681 is an apocalyptic number.

It is an amenable number.

665250450681 is a deficient number, since it is larger than the sum of its proper divisors (225023216263).

665250450681 is a wasteful number, since it uses less digits than its factorization.

665250450681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 818266511.

The product of its (nonzero) digits is 1728000, while the sum is 48.

The spelling of 665250450681 in words is "six hundred sixty-five billion, two hundred fifty million, four hundred fifty thousand, six hundred eighty-one".