18428551 has 4 divisors (see below), whose sum is σ = 18703672. Its totient is φ = 18153432.

The previous prime is 18428549. The next prime is 18428563. The reversal of 18428551 is 15582481.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 18428551 - 2¹ = 18428549 is a prime.

It is a super-2 number, since 2×18428551² = 679222983919202, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18428581) 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, 137460 + ... + 137593.

It is an arithmetic number, because the mean of its divisors is an integer number (4675918).

Almost surely, 2^18428551 is an apocalyptic number.

18428551 is a deficient number, since it is larger than the sum of its proper divisors (275121).

18428551 is an equidigital number, since it uses as much as digits as its factorization.

18428551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 275120.

The product of its digits is 12800, while the sum is 34.

The square root of 18428551 is about 4292.8488210045. The cubic root of 18428551 is about 264.1377026872.

The spelling of 18428551 in words is "eighteen million, four hundred twenty-eight thousand, five hundred fifty-one".