181690145 has 32 divisors (see below), whose sum is σ = 269837568. Its totient is φ = 114363648.

The previous prime is 181690123. The next prime is 181690151. The reversal of 181690145 is 541096181.

181690145 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 181690145 - 2⁶ = 181690081 is a prime.

It is a super-2 number, since 2×181690145² = 66022617580242050, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (35).

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

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 88622 + ... + 90648.

It is an arithmetic number, because the mean of its divisors is an integer number (8432424).

Almost surely, 2^181690145 is an apocalyptic number.

It is an amenable number.

181690145 is a deficient number, since it is larger than the sum of its proper divisors (88147423).

181690145 is a wasteful number, since it uses less digits than its factorization.

181690145 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2249.

The product of its (nonzero) digits is 8640, while the sum is 35.

The square root of 181690145 is about 13479.2486808427. The cubic root of 181690145 is about 566.3833229756.

The spelling of 181690145 in words is "one hundred eighty-one million, six hundred ninety thousand, one hundred forty-five".