165870787 has 4 divisors (see below), whose sum is σ = 166267080. Its totient is φ = 165474496.

The previous prime is 165870721. The next prime is 165870791. The reversal of 165870787 is 787078561.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 165870787 - 2²³ = 157482179 is a prime.

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is an alternating number because its digits alternate between odd and even.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 165870787.

It is not an unprimeable number, because it can be changed into a prime (165870587) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 197518 + ... + 198355.

It is an arithmetic number, because the mean of its divisors is an integer number (41566770).

Almost surely, 2^165870787 is an apocalyptic number.

165870787 is a deficient number, since it is larger than the sum of its proper divisors (396293).

165870787 is an equidigital number, since it uses as much as digits as its factorization.

165870787 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 396292.

The product of its (nonzero) digits is 658560, while the sum is 49.

The square root of 165870787 is about 12879.0833136524. The cubic root of 165870787 is about 549.4438311712.

The spelling of 165870787 in words is "one hundred sixty-five million, eight hundred seventy thousand, seven hundred eighty-seven".