18070731 has 24 divisors (see below), whose sum is σ = 29949920. Its totient is φ = 10285056.

The previous prime is 18070727. The next prime is 18070733. The reversal of 18070731 is 13707081.

It is not a de Polignac number, because 18070731 - 2² = 18070727 is a prime.

It is a super-2 number, since 2×18070731² = 653102637748722, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 18070695 and 18070704.

It is not an unprimeable number, because it can be changed into a prime (18070733) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 23115 + ... + 23883.

Almost surely, 2^18070731 is an apocalyptic number.

18070731 is a deficient number, since it is larger than the sum of its proper divisors (11879189).

18070731 is a wasteful number, since it uses less digits than its factorization.

18070731 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1155 (or 1152 counting only the distinct ones).

The product of its (nonzero) digits is 1176, while the sum is 27.

The square root of 18070731 is about 4250.9682426478. The cubic root of 18070731 is about 262.4169642125.

The spelling of 18070731 in words is "eighteen million, seventy thousand, seven hundred thirty-one".