18905121 has 6 divisors (see below), whose sum is σ = 27307410. Its totient is φ = 12603408.

The previous prime is 18905119. The next prime is 18905143. The reversal of 18905121 is 12150981.

It can be written as a sum of positive squares in only one way, i.e., 18792225 + 112896 = 4335^2 + 336^2 .

It is not a de Polignac number, because 18905121 - 2¹ = 18905119 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (18905101) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1050276 + ... + 1050293.

It is an arithmetic number, because the mean of its divisors is an integer number (4551235).

Almost surely, 2^18905121 is an apocalyptic number.

It is an amenable number.

18905121 is a deficient number, since it is larger than the sum of its proper divisors (8402289).

18905121 is a wasteful number, since it uses less digits than its factorization.

18905121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2100575 (or 2100572 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 27.

The square root of 18905121 is about 4348.0019549214. The cubic root of 18905121 is about 266.3952563206.

The spelling of 18905121 in words is "eighteen million, nine hundred five thousand, one hundred twenty-one".