38447681 has 2 divisors, whose sum is σ = 38447682. Its totient is φ = 38447680.

The previous prime is 38447677. The next prime is 38447683. The reversal of 38447681 is 18674483.

38447681 = 4384² + 4385².

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19228225 + 19219456 = 4385^2 + 4384^2 .

It is a cyclic number.

It is not a de Polignac number, because 38447681 - 2² = 38447677 is a prime.

It is a super-2 number, since 2×38447681² = 2956448348555522, which contains 22 as substring.

Together with 38447683, 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 (38447683) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19223840 + 19223841.

It is an arithmetic number, because the mean of its divisors is an integer number (19223841).

Almost surely, 2^38447681 is an apocalyptic number.

38447681 is the 4385-th centered square number.

It is an amenable number.

38447681 is a deficient number, since it is larger than the sum of its proper divisors (1).

38447681 is an equidigital number, since it uses as much as digits as its factorization.

38447681 is an evil number, because the sum of its binary digits is even.

The product of its digits is 129024, while the sum is 41.

The square root of 38447681 is about 6200.6194045434. The cubic root of 38447681 is about 337.5126462568.

The spelling of 38447681 in words is "thirty-eight million, four hundred forty-seven thousand, six hundred eighty-one".