39681949 has 2 divisors, whose sum is σ = 39681950. Its totient is φ = 39681948.

The previous prime is 39681919. The next prime is 39682003. The reversal of 39681949 is 94918693.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21252100 + 18429849 = 4610^2 + 4293^2 .

It is a cyclic number.

It is not a de Polignac number, because 39681949 - 2⁷ = 39681821 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (39681919) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19840974 + 19840975.

It is an arithmetic number, because the mean of its divisors is an integer number (19840975).

Almost surely, 2^39681949 is an apocalyptic number.

It is an amenable number.

39681949 is a deficient number, since it is larger than the sum of its proper divisors (1).

39681949 is an equidigital number, since it uses as much as digits as its factorization.

39681949 is an evil number, because the sum of its binary digits is even.

The product of its digits is 419904, while the sum is 49.

The square root of 39681949 is about 6299.3609993395. The cubic root of 39681949 is about 341.0863436350.

The spelling of 39681949 in words is "thirty-nine million, six hundred eighty-one thousand, nine hundred forty-nine".