18742681 has 2 divisors, whose sum is σ = 18742682. Its totient is φ = 18742680.

The previous prime is 18742679. The next prime is 18742727. The reversal of 18742681 is 18624781.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17264025 + 1478656 = 4155^2 + 1216^2 .

It is a cyclic number.

It is not a de Polignac number, because 18742681 - 2¹ = 18742679 is a prime.

It is a super-2 number, since 2×18742681² = 702576182135522, which contains 22 as substring.

Together with 18742679, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 18742681.

It is not a weakly prime, because it can be changed into another prime (18742181) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9371340 + 9371341.

It is an arithmetic number, because the mean of its divisors is an integer number (9371341).

Almost surely, 2^18742681 is an apocalyptic number.

It is an amenable number.

18742681 is a deficient number, since it is larger than the sum of its proper divisors (1).

18742681 is an equidigital number, since it uses as much as digits as its factorization.

18742681 is an evil number, because the sum of its binary digits is even.

The product of its digits is 21504, while the sum is 37.

The square root of 18742681 is about 4329.2818111091. The cubic root of 18742681 is about 265.6300706944.

The spelling of 18742681 in words is "eighteen million, seven hundred forty-two thousand, six hundred eighty-one".