18828731 has 4 divisors (see below), whose sum is σ = 18837552. Its totient is φ = 18819912.

The previous prime is 18828721. The next prime is 18828737. The reversal of 18828731 is 13782881.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 13782881 = 7 ⋅1968983.

It is a cyclic number.

It is not a de Polignac number, because 18828731 - 2¹⁴ = 18812347 is a prime.

It is a super-2 number, since 2×18828731² = 709042222140722, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18828737) 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, 1025 + ... + 6221.

It is an arithmetic number, because the mean of its divisors is an integer number (4709388).

Almost surely, 2^18828731 is an apocalyptic number.

18828731 is a deficient number, since it is larger than the sum of its proper divisors (8821).

18828731 is an equidigital number, since it uses as much as digits as its factorization.

18828731 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8820.

The product of its digits is 21504, while the sum is 38.

The square root of 18828731 is about 4339.2085683912. The cubic root of 18828731 is about 266.0359638185.

The spelling of 18828731 in words is "eighteen million, eight hundred twenty-eight thousand, seven hundred thirty-one".