18061731 has 16 divisors (see below), whose sum is σ = 26857600. Its totient is φ = 11996424.

The previous prime is 18061721. The next prime is 18061741. The reversal of 18061731 is 13716081.

18061731 is a `hidden beast` number, since 18 + 0 + 617 + 31 = 666.

It is an interprime number because it is at equal distance from previous prime (18061721) and next prime (18061741).

It is not a de Polignac number, because 18061731 - 2⁵ = 18061699 is a prime.

It is a super-2 number, since 2×18061731² = 652452253432722, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 18061695 and 18061704.

It is not an unprimeable number, because it can be changed into a prime (18061721) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7200 + ... + 9378.

It is an arithmetic number, because the mean of its divisors is an integer number (1678600).

Almost surely, 2^18061731 is an apocalyptic number.

18061731 is a deficient number, since it is larger than the sum of its proper divisors (8795869).

18061731 is a wasteful number, since it uses less digits than its factorization.

18061731 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2495 (or 2489 counting only the distinct ones).

The product of its (nonzero) digits is 1008, while the sum is 27.

The square root of 18061731 is about 4249.9095284488. The cubic root of 18061731 is about 262.3733920060.

The spelling of 18061731 in words is "eighteen million, sixty-one thousand, seven hundred thirty-one".