18061643 has 2 divisors, whose sum is σ = 18061644. Its totient is φ = 18061642.

The previous prime is 18061639. The next prime is 18061651. The reversal of 18061643 is 34616081.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 18061643 - 2² = 18061639 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (18061663) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9030821 + 9030822.

It is an arithmetic number, because the mean of its divisors is an integer number (9030822).

Almost surely, 2^18061643 is an apocalyptic number.

18061643 is a deficient number, since it is larger than the sum of its proper divisors (1).

18061643 is an equidigital number, since it uses as much as digits as its factorization.

18061643 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3456, while the sum is 29.

The square root of 18061643 is about 4249.8991752746. The cubic root of 18061643 is about 262.3729658952.

The spelling of 18061643 in words is "eighteen million, sixty-one thousand, six hundred forty-three".