189791865 has 12 divisors (see below), whose sum is σ = 328972644. Its totient is φ = 101222304.

The previous prime is 189791839. The next prime is 189791881. The reversal of 189791865 is 568197981.

It can be written as a sum of positive squares in 2 ways, for example, as 66781584 + 123010281 = 8172^2 + 11091^2 .

It is not a de Polignac number, because 189791865 - 2¹² = 189787769 is a prime.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2108754 + ... + 2108843.

It is an arithmetic number, because the mean of its divisors is an integer number (27414387).

Almost surely, 2^189791865 is an apocalyptic number.

189791865 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

189791865 is a deficient number, since it is larger than the sum of its proper divisors (139180779).

189791865 is a wasteful number, since it uses less digits than its factorization.

189791865 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4217608 (or 4217605 counting only the distinct ones).

The product of its digits is 1088640, while the sum is 54.

The square root of 189791865 is about 13776.4968333753. The cubic root of 189791865 is about 574.6797107230.

The spelling of 189791865 in words is "one hundred eighty-nine million, seven hundred ninety-one thousand, eight hundred sixty-five".