18133731 has 48 divisors (see below), whose sum is σ = 33067008. Its totient is φ = 9302400.

The previous prime is 18133727. The next prime is 18133777. The reversal of 18133731 is 13733181.

It is not a de Polignac number, because 18133731 - 2² = 18133727 is a prime.

It is a super-2 number, since 2×18133731² = 657664399960722, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 18133695 and 18133704.

It is not an unprimeable number, because it can be changed into a prime (18133721) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 94846 + ... + 95036.

It is an arithmetic number, because the mean of its divisors is an integer number (688896).

Almost surely, 2^18133731 is an apocalyptic number.

18133731 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

18133731 is a deficient number, since it is larger than the sum of its proper divisors (14933277).

18133731 is a wasteful number, since it uses less digits than its factorization.

18133731 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 352 (or 349 counting only the distinct ones).

The product of its digits is 1512, while the sum is 27.

The square root of 18133731 is about 4258.3718719717. The cubic root of 18133731 is about 262.7215653143.

The spelling of 18133731 in words is "eighteen million, one hundred thirty-three thousand, seven hundred thirty-one".