18628831 has 4 divisors (see below), whose sum is σ = 20061832. Its totient is φ = 17195832.

The previous prime is 18628823. The next prime is 18628853. The reversal of 18628831 is 13882681.

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 18628831 - 2³ = 18628823 is a prime.

It is a super-2 number, since 2×18628831² = 694066688853122, 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 (18628031) 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, 716481 + ... + 716506.

It is an arithmetic number, because the mean of its divisors is an integer number (5015458).

Almost surely, 2^18628831 is an apocalyptic number.

18628831 is a deficient number, since it is larger than the sum of its proper divisors (1433001).

18628831 is a wasteful number, since it uses less digits than its factorization.

18628831 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1433000.

The product of its digits is 18432, while the sum is 37.

The square root of 18628831 is about 4316.1129503293. The cubic root of 18628831 is about 265.0911327714.

It can be divided in two parts, 18 and 628831, that added together give a square (628849 = 793²).

The spelling of 18628831 in words is "eighteen million, six hundred twenty-eight thousand, eight hundred thirty-one".