665650899 has 8 divisors (see below), whose sum is σ = 986149520. Its totient is φ = 443767248.

The previous prime is 665650877. The next prime is 665650927. The reversal of 665650899 is 998056566.

It is not a de Polignac number, because 665650899 - 2¹³ = 665642707 is a prime.

It is a super-2 number, since 2×665650899² = 886182238679016402, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (665652899) 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, 12326842 + ... + 12326895.

It is an arithmetic number, because the mean of its divisors is an integer number (123268690).

Almost surely, 2^665650899 is an apocalyptic number.

665650899 is a deficient number, since it is larger than the sum of its proper divisors (320498621).

665650899 is a wasteful number, since it uses less digits than its factorization.

665650899 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24653746 (or 24653740 counting only the distinct ones).

The product of its (nonzero) digits is 3499200, while the sum is 54.

The square root of 665650899 is about 25800.2112200656. The cubic root of 665650899 is about 873.1365618136.

The spelling of 665650899 in words is "six hundred sixty-five million, six hundred fifty thousand, eight hundred ninety-nine".