39939281 has 2 divisors, whose sum is σ = 39939282. Its totient is φ = 39939280.

The previous prime is 39939271. The next prime is 39939329. The reversal of 39939281 is 18293993.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 30691600 + 9247681 = 5540^2 + 3041^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-39939281 is a prime.

It is a super-2 number, since 2×39939281² = 3190292333593922, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (39939271) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19969640 + 19969641.

It is an arithmetic number, because the mean of its divisors is an integer number (19969641).

Almost surely, 2^39939281 is an apocalyptic number.

It is an amenable number.

39939281 is a deficient number, since it is larger than the sum of its proper divisors (1).

39939281 is an equidigital number, since it uses as much as digits as its factorization.

39939281 is an evil number, because the sum of its binary digits is even.

The product of its digits is 104976, while the sum is 44.

The square root of 39939281 is about 6319.7532388536. The cubic root of 39939281 is about 341.8220549854.

The spelling of 39939281 in words is "thirty-nine million, nine hundred thirty-nine thousand, two hundred eighty-one".