18891845 has 16 divisors (see below), whose sum is σ = 27433728. Its totient is φ = 12192000.

The previous prime is 18891841. The next prime is 18891853. The reversal of 18891845 is 54819881.

It is not a de Polignac number, because 18891845 - 2² = 18891841 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 18891796 and 18891805.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18891841) 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, 15281 + ... + 16470.

It is an arithmetic number, because the mean of its divisors is an integer number (1714608).

Almost surely, 2^18891845 is an apocalyptic number.

It is an amenable number.

18891845 is a deficient number, since it is larger than the sum of its proper divisors (8541883).

18891845 is a wasteful number, since it uses less digits than its factorization.

18891845 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31780.

The product of its digits is 92160, while the sum is 44.

The square root of 18891845 is about 4346.4750085558. The cubic root of 18891845 is about 266.3328835978.

Subtracting 18891845 from its reverse (54819881), we obtain a square (35928036 = 5994²).

The spelling of 18891845 in words is "eighteen million, eight hundred ninety-one thousand, eight hundred forty-five".