18888121 has 4 divisors (see below), whose sum is σ = 21586432. Its totient is φ = 16189812.

The previous prime is 18888119. The next prime is 18888151. The reversal of 18888121 is 12188881.

18888121 = 650² + 651² + ... + 691².

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 18888121 - 2¹ = 18888119 is a prime.

It is a super-2 number, since 2×18888121² = 713522229821282, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (18888151) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1349145 + ... + 1349158.

It is an arithmetic number, because the mean of its divisors is an integer number (5396608).

Almost surely, 2^18888121 is an apocalyptic number.

It is an amenable number.

18888121 is a deficient number, since it is larger than the sum of its proper divisors (2698311).

18888121 is an equidigital number, since it uses as much as digits as its factorization.

18888121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2698310.

The product of its digits is 8192, while the sum is 37.

The square root of 18888121 is about 4346.0465943199. The cubic root of 18888121 is about 266.3153824161.

The spelling of 18888121 in words is "eighteen million, eight hundred eighty-eight thousand, one hundred twenty-one".