18613121 has 4 divisors (see below), whose sum is σ = 18622512. Its totient is φ = 18603732.

The previous prime is 18613117. The next prime is 18613129. The reversal of 18613121 is 12131681.

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, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 18613121 - 2² = 18613117 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18613129) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 431 + ... + 6116.

It is an arithmetic number, because the mean of its divisors is an integer number (4655628).

Almost surely, 2^18613121 is an apocalyptic number.

It is an amenable number.

18613121 is a deficient number, since it is larger than the sum of its proper divisors (9391).

18613121 is an equidigital number, since it uses as much as digits as its factorization.

18613121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9390.

The product of its digits is 288, while the sum is 23.

The square root of 18613121 is about 4314.2926419055. The cubic root of 18613121 is about 265.0165932413.

The spelling of 18613121 in words is "eighteen million, six hundred thirteen thousand, one hundred twenty-one".