18077861 has 2 divisors, whose sum is σ = 18077862. Its totient is φ = 18077860.

The previous prime is 18077849. The next prime is 18077863. The reversal of 18077861 is 16877081.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11600836 + 6477025 = 3406^2 + 2545^2 .

It is a cyclic number.

It is not a de Polignac number, because 18077861 - 2¹⁰ = 18076837 is a prime.

Together with 18077863, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18077863) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9038930 + 9038931.

It is an arithmetic number, because the mean of its divisors is an integer number (9038931).

Almost surely, 2^18077861 is an apocalyptic number.

It is an amenable number.

18077861 is a deficient number, since it is larger than the sum of its proper divisors (1).

18077861 is an equidigital number, since it uses as much as digits as its factorization.

18077861 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 18816, while the sum is 38.

The square root of 18077861 is about 4251.8067924119. The cubic root of 18077861 is about 262.4514728134.

The spelling of 18077861 in words is "eighteen million, seventy-seven thousand, eight hundred sixty-one".