18428687 has 4 divisors (see below), whose sum is σ = 18569496. Its totient is φ = 18287880.

The previous prime is 18428633. The next prime is 18428713. The reversal of 18428687 is 78682481.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 78682481 = 29 ⋅2713189.

It is a cyclic number.

It is not a de Polignac number, because 18428687 - 2⁶ = 18428623 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18428887) 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, 70208 + ... + 70469.

It is an arithmetic number, because the mean of its divisors is an integer number (4642374).

Almost surely, 2^18428687 is an apocalyptic number.

18428687 is a deficient number, since it is larger than the sum of its proper divisors (140809).

18428687 is a wasteful number, since it uses less digits than its factorization.

18428687 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 140808.

The product of its digits is 172032, while the sum is 44.

The square root of 18428687 is about 4292.8646612722. The cubic root of 18428687 is about 264.1383524514.

The spelling of 18428687 in words is "eighteen million, four hundred twenty-eight thousand, six hundred eighty-seven".