18039401 has 2 divisors, whose sum is σ = 18039402. Its totient is φ = 18039400.

The previous prime is 18039389. The next prime is 18039419. The reversal of 18039401 is 10493081.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 10394176 + 7645225 = 3224^2 + 2765^2 .

It is an emirp because it is prime and its reverse (10493081) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18039401 - 2¹⁴ = 18023017 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (18039491) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9019700 + 9019701.

It is an arithmetic number, because the mean of its divisors is an integer number (9019701).

Almost surely, 2^18039401 is an apocalyptic number.

It is an amenable number.

18039401 is a deficient number, since it is larger than the sum of its proper divisors (1).

18039401 is an equidigital number, since it uses as much as digits as its factorization.

18039401 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 864, while the sum is 26.

The square root of 18039401 is about 4247.2816012127. The cubic root of 18039401 is about 262.2652219761.

The spelling of 18039401 in words is "eighteen million, thirty-nine thousand, four hundred one".