39956381 has 2 divisors, whose sum is σ = 39956382. Its totient is φ = 39956380.

The previous prime is 39956377. The next prime is 39956387. The reversal of 39956381 is 18365993.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 37100281 + 2856100 = 6091^2 + 1690^2 .

It is an emirp because it is prime and its reverse (18365993) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 39956381 - 2² = 39956377 is a prime.

It is a super-2 number, since 2×39956381² = 3193024765234322, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (39956387) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19978190 + 19978191.

It is an arithmetic number, because the mean of its divisors is an integer number (19978191).

Almost surely, 2^39956381 is an apocalyptic number.

It is an amenable number.

39956381 is a deficient number, since it is larger than the sum of its proper divisors (1).

39956381 is an equidigital number, since it uses as much as digits as its factorization.

39956381 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 174960, while the sum is 44.

The square root of 39956381 is about 6321.1059949980. The cubic root of 39956381 is about 341.8708317201.

The spelling of 39956381 in words is "thirty-nine million, nine hundred fifty-six thousand, three hundred eighty-one".