165990719 has 4 divisors (see below), whose sum is σ = 166735296. Its totient is φ = 165246144.

The previous prime is 165990679. The next prime is 165990733. The reversal of 165990719 is 917099561.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-165990719 is a prime.

It is a super-2 number, since 2×165990719² = 55105837588273922, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (165990749) 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, 371954 + ... + 372399.

It is an arithmetic number, because the mean of its divisors is an integer number (41683824).

Almost surely, 2^165990719 is an apocalyptic number.

165990719 is a deficient number, since it is larger than the sum of its proper divisors (744577).

165990719 is an equidigital number, since it uses as much as digits as its factorization.

165990719 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 744576.

The product of its (nonzero) digits is 153090, while the sum is 47.

The square root of 165990719 is about 12883.7385490393. The cubic root of 165990719 is about 549.5762234251.

The spelling of 165990719 in words is "one hundred sixty-five million, nine hundred ninety thousand, seven hundred nineteen".