18280861 has 2 divisors, whose sum is σ = 18280862. Its totient is φ = 18280860.

The previous prime is 18280771. The next prime is 18280877. The reversal of 18280861 is 16808281.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18232900 + 47961 = 4270^2 + 219^2 .

It is a cyclic number.

It is not a de Polignac number, because 18280861 - 2¹³ = 18272669 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18280961) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9140430 + 9140431.

It is an arithmetic number, because the mean of its divisors is an integer number (9140431).

Almost surely, 2^18280861 is an apocalyptic number.

It is an amenable number.

18280861 is a deficient number, since it is larger than the sum of its proper divisors (1).

18280861 is an equidigital number, since it uses as much as digits as its factorization.

18280861 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6144, while the sum is 34.

The square root of 18280861 is about 4275.6123538038. The cubic root of 18280861 is about 263.4301922528.

The spelling of 18280861 in words is "eighteen million, two hundred eighty thousand, eight hundred sixty-one".