39985987 has 2 divisors, whose sum is σ = 39985988. Its totient is φ = 39985986.

The previous prime is 39985951. The next prime is 39985999. The reversal of 39985987 is 78958993.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 39985987 - 2¹⁹ = 39461699 is a prime.

It is not a weakly prime, because it can be changed into another prime (39985087) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19992993 + 19992994.

It is an arithmetic number, because the mean of its divisors is an integer number (19992994).

Almost surely, 2^39985987 is an apocalyptic number.

39985987 is a deficient number, since it is larger than the sum of its proper divisors (1).

39985987 is an equidigital number, since it uses as much as digits as its factorization.

39985987 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4898880, while the sum is 58.

The square root of 39985987 is about 6323.4473983738. The cubic root of 39985987 is about 341.9552481826.

The spelling of 39985987 in words is "thirty-nine million, nine hundred eighty-five thousand, nine hundred eighty-seven".