665065027891 has 8 divisors (see below), whose sum is σ = 729284686704. Its totient is φ = 601471902720.

The previous prime is 665065027889. The next prime is 665065027897. The reversal of 665065027891 is 198720560566.

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 665065027891 - 2¹ = 665065027889 is a prime.

It is a super-2 number, since 2×665065027891² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (665065027897) 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, 156631186 + ... + 156635431.

It is an arithmetic number, because the mean of its divisors is an integer number (91160585838).

Almost surely, 2^665065027891 is an apocalyptic number.

665065027891 is a deficient number, since it is larger than the sum of its proper divisors (64219658813).

665065027891 is a wasteful number, since it uses less digits than its factorization.

665065027891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 313266821.

The product of its (nonzero) digits is 5443200, while the sum is 55.

The spelling of 665065027891 in words is "six hundred sixty-five billion, sixty-five million, twenty-seven thousand, eight hundred ninety-one".