39938687906 has 16 divisors (see below), whose sum is σ = 64546621944. Its totient is φ = 18424589184.

The previous prime is 39938687881. The next prime is 39938687909. The reversal of 39938687906 is 60978683993.

It can be written as a sum of positive squares in 4 ways, for example, as 3689955025 + 36248732881 = 60745^2 + 190391^2 .

It is not an unprimeable number, because it can be changed into a prime (39938687909) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 303845 + ... + 414968.

Almost surely, 2^39938687906 is an apocalyptic number.

39938687906 is a deficient number, since it is larger than the sum of its proper divisors (24607934038).

39938687906 is a wasteful number, since it uses less digits than its factorization.

39938687906 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 720965.

The product of its (nonzero) digits is 105815808, while the sum is 68.

The spelling of 39938687906 in words is "thirty-nine billion, nine hundred thirty-eight million, six hundred eighty-seven thousand, nine hundred six".