39481681 has 2 divisors, whose sum is σ = 39481682. Its totient is φ = 39481680.

The previous prime is 39481649. The next prime is 39481709. The reversal of 39481681 is 18618493.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 33454656 + 6027025 = 5784^2 + 2455^2 .

It is a cyclic number.

It is not a de Polignac number, because 39481681 - 2⁵ = 39481649 is a prime.

It is a super-2 number, since 2×39481681² = 3117606269171522, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (39581681) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19740840 + 19740841.

It is an arithmetic number, because the mean of its divisors is an integer number (19740841).

Almost surely, 2^39481681 is an apocalyptic number.

It is an amenable number.

39481681 is a deficient number, since it is larger than the sum of its proper divisors (1).

39481681 is an equidigital number, since it uses as much as digits as its factorization.

39481681 is an evil number, because the sum of its binary digits is even.

The product of its digits is 41472, while the sum is 40.

The square root of 39481681 is about 6283.4449945870. Note that the first 3 decimals coincide. The cubic root of 39481681 is about 340.5115741748.

It can be divided in two parts, 3948168 and 1, that added together give a square (3948169 = 1987²).

The spelling of 39481681 in words is "thirty-nine million, four hundred eighty-one thousand, six hundred eighty-one".