16290181 has 4 divisors (see below), whose sum is σ = 16380364. Its totient is φ = 16200000.

The previous prime is 16290173. The next prime is 16290191. The reversal of 16290181 is 18109261.

It is a happy number.

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

It can be written as a sum of positive squares in 2 ways, for example, as 8946081 + 7344100 = 2991^2 + 2710^2 .

It is a 5-Lehmer number, since φ(16290181) divides (16290181-1)⁵.

It is a cyclic number.

It is not a de Polignac number, because 16290181 - 2³ = 16290173 is a prime.

It is a super-2 number, since 2×16290181² = 530739994025522, 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 (16290121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 44820 + ... + 45181.

It is an arithmetic number, because the mean of its divisors is an integer number (4095091).

Almost surely, 2^16290181 is an apocalyptic number.

It is an amenable number.

16290181 is a deficient number, since it is larger than the sum of its proper divisors (90183).

16290181 is an equidigital number, since it uses as much as digits as its factorization.

16290181 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 90182.

The product of its (nonzero) digits is 864, while the sum is 28.

The square root of 16290181 is about 4036.1096367666. The cubic root of 16290181 is about 253.4984471089.

It can be divided in two parts, 16290 and 181, that added together give a triangular number (16471 = T₁₈₁).

The spelling of 16290181 in words is "sixteen million, two hundred ninety thousand, one hundred eighty-one".