39687971 has 2 divisors, whose sum is σ = 39687972. Its totient is φ = 39687970.

The previous prime is 39687953. The next prime is 39687997. The reversal of 39687971 is 17978693.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-39687971 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (39687671) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19843985 + 19843986.

It is an arithmetic number, because the mean of its divisors is an integer number (19843986).

Almost surely, 2^39687971 is an apocalyptic number.

39687971 is a deficient number, since it is larger than the sum of its proper divisors (1).

39687971 is an equidigital number, since it uses as much as digits as its factorization.

39687971 is an evil number, because the sum of its binary digits is even.

The product of its digits is 571536, while the sum is 50.

The square root of 39687971 is about 6299.8389661959. The cubic root of 39687971 is about 341.1035968036.

The spelling of 39687971 in words is "thirty-nine million, six hundred eighty-seven thousand, nine hundred seventy-one".