18028831 has 4 divisors (see below), whose sum is σ = 18042472. Its totient is φ = 18015192.

The previous prime is 18028783. The next prime is 18028837. The reversal of 18028831 is 13882081.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 13882081 = 17 ⋅816593.

It is a cyclic number.

It is not a de Polignac number, because 18028831 - 2⁹ = 18028319 is a prime.

It is a super-2 number, since 2×18028831² = 650077494453122, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 18028793 and 18028802.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18028837) 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, 4596 + ... + 7561.

It is an arithmetic number, because the mean of its divisors is an integer number (4510618).

Almost surely, 2^18028831 is an apocalyptic number.

18028831 is a deficient number, since it is larger than the sum of its proper divisors (13641).

18028831 is a wasteful number, since it uses less digits than its factorization.

18028831 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13640.

The product of its (nonzero) digits is 3072, while the sum is 31.

The square root of 18028831 is about 4246.0370935733. The cubic root of 18028831 is about 262.2139881055.

The spelling of 18028831 in words is "eighteen million, twenty-eight thousand, eight hundred thirty-one".