18887121 has 32 divisors (see below), whose sum is σ = 32140800. Its totient is φ = 10841040.

The previous prime is 18887047. The next prime is 18887123. The reversal of 18887121 is 12178881.

It is not a de Polignac number, because 18887121 - 2¹⁹ = 18362833 is a prime.

It is not an unprimeable number, because it can be changed into a prime (18887123) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3970 + ... + 7316.

It is an arithmetic number, because the mean of its divisors is an integer number (1004400).

Almost surely, 2^18887121 is an apocalyptic number.

18887121 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

18887121 is a deficient number, since it is larger than the sum of its proper divisors (13253679).

18887121 is a wasteful number, since it uses less digits than its factorization.

18887121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3386 (or 3380 counting only the distinct ones).

The product of its digits is 7168, while the sum is 36.

The square root of 18887121 is about 4345.9315457103. The cubic root of 18887121 is about 266.3106824589.

It can be divided in two parts, 1888 and 7121, that added together give a palindrome (9009).

The spelling of 18887121 in words is "eighteen million, eight hundred eighty-seven thousand, one hundred twenty-one".