38947681 has 2 divisors, whose sum is σ = 38947682. Its totient is φ = 38947680.

The previous prime is 38947669. The next prime is 38947691. The reversal of 38947681 is 18674983.

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., 32672656 + 6275025 = 5716^2 + 2505^2 .

It is an emirp because it is prime and its reverse (18674983) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-38947681 is a prime.

It is a super-2 number, since 2×38947681² = 3033843710555522, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (38947621) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19473840 + 19473841.

It is an arithmetic number, because the mean of its divisors is an integer number (19473841).

Almost surely, 2^38947681 is an apocalyptic number.

It is an amenable number.

38947681 is a deficient number, since it is larger than the sum of its proper divisors (1).

38947681 is an equidigital number, since it uses as much as digits as its factorization.

38947681 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 290304, while the sum is 46.

The square root of 38947681 is about 6240.8077201593. The cubic root of 38947681 is about 338.9694313186.

The spelling of 38947681 in words is "thirty-eight million, nine hundred forty-seven thousand, six hundred eighty-one".