18120621 has 8 divisors (see below), whose sum is σ = 24994080. Its totient is φ = 11663792.

The previous prime is 18120607. The next prime is 18120637. The reversal of 18120621 is 12602181.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 18120621 - 2¹⁴ = 18104237 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18127621) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 104055 + ... + 104228.

It is an arithmetic number, because the mean of its divisors is an integer number (3124260).

Almost surely, 2^18120621 is an apocalyptic number.

It is an amenable number.

18120621 is a deficient number, since it is larger than the sum of its proper divisors (6873459).

18120621 is a wasteful number, since it uses less digits than its factorization.

18120621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 208315.

The product of its (nonzero) digits is 192, while the sum is 21.

The square root of 18120621 is about 4256.8322729466. The cubic root of 18120621 is about 262.6582374736.

It can be divided in two parts, 181 and 20621, that added together give a palindrome (20802).

The spelling of 18120621 in words is "eighteen million, one hundred twenty thousand, six hundred twenty-one".