18426987 has 32 divisors (see below), whose sum is σ = 28339200. Its totient is φ = 11827296.

The previous prime is 18426973. The next prime is 18427021. The reversal of 18426987 is 78962481.

It is not a de Polignac number, because 18426987 - 2⁴ = 18426971 is a prime.

It is not an unprimeable number, because it can be changed into a prime (18426907) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 112968 + ... + 113130.

It is an arithmetic number, because the mean of its divisors is an integer number (885600).

Almost surely, 2^18426987 is an apocalyptic number.

18426987 is a deficient number, since it is larger than the sum of its proper divisors (9912213).

18426987 is a wasteful number, since it uses less digits than its factorization.

18426987 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 304 (or 298 counting only the distinct ones).

The product of its digits is 193536, while the sum is 45.

The square root of 18426987 is about 4292.6666537247. Note that the first 4 decimals coincide. The cubic root of 18426987 is about 264.1302301689.

The spelling of 18426987 in words is "eighteen million, four hundred twenty-six thousand, nine hundred eighty-seven".