38918681 has 2 divisors, whose sum is σ = 38918682. Its totient is φ = 38918680.

The previous prime is 38918657. The next prime is 38918683. The reversal of 38918681 is 18681983.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 33235225 + 5683456 = 5765^2 + 2384^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-38918681 is a prime.

It is a super-2 number, since 2×38918681² = 3029327461559522, which contains 22 as substring.

Together with 38918683, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (38918683) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19459340 + 19459341.

It is an arithmetic number, because the mean of its divisors is an integer number (19459341).

Almost surely, 2^38918681 is an apocalyptic number.

It is an amenable number.

38918681 is a deficient number, since it is larger than the sum of its proper divisors (1).

38918681 is an equidigital number, since it uses as much as digits as its factorization.

38918681 is an evil number, because the sum of its binary digits is even.

The product of its digits is 82944, while the sum is 44.

The square root of 38918681 is about 6238.4838703005. The cubic root of 38918681 is about 338.8852795021.

The spelling of 38918681 in words is "thirty-eight million, nine hundred eighteen thousand, six hundred eighty-one".