18891145 has 16 divisors (see below), whose sum is σ = 27901440. Its totient is φ = 11957184.

The previous prime is 18891143. The next prime is 18891193. The reversal of 18891145 is 54119881.

It is a cyclic number.

It is not a de Polignac number, because 18891145 - 2¹ = 18891143 is a prime.

It is a super-2 number, since 2×18891145² = 713750718822050, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (18891143) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 20305 + ... + 21214.

It is an arithmetic number, because the mean of its divisors is an integer number (1743840).

Almost surely, 2^18891145 is an apocalyptic number.

It is an amenable number.

18891145 is a deficient number, since it is larger than the sum of its proper divisors (9010295).

18891145 is a wasteful number, since it uses less digits than its factorization.

18891145 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41544.

The product of its digits is 11520, while the sum is 37.

The square root of 18891145 is about 4346.3944827869. The cubic root of 18891145 is about 266.3295940776.

The spelling of 18891145 in words is "eighteen million, eight hundred ninety-one thousand, one hundred forty-five".