18861377 has 2 divisors, whose sum is σ = 18861378. Its totient is φ = 18861376.

The previous prime is 18861343. The next prime is 18861407. The reversal of 18861377 is 77316881.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15178816 + 3682561 = 3896^2 + 1919^2 .

It is a cyclic number.

It is not a de Polignac number, because 18861377 - 2⁸ = 18861121 is a prime.

It is a super-2 number, since 2×18861377² = 711503084672258, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (18861307) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9430688 + 9430689.

It is an arithmetic number, because the mean of its divisors is an integer number (9430689).

Almost surely, 2^18861377 is an apocalyptic number.

It is an amenable number.

18861377 is a deficient number, since it is larger than the sum of its proper divisors (1).

18861377 is an equidigital number, since it uses as much as digits as its factorization.

18861377 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 56448, while the sum is 41.

The square root of 18861377 is about 4342.9686851277. The cubic root of 18861377 is about 266.1896296078.

The spelling of 18861377 in words is "eighteen million, eight hundred sixty-one thousand, three hundred seventy-seven".