39981941906 has 4 divisors (see below), whose sum is σ = 59972912862. Its totient is φ = 19990970952.

The previous prime is 39981941893. The next prime is 39981941917. The reversal of 39981941906 is 60914918993.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 26909449681 + 13072492225 = 164041^2 + 114335^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9995485475 + ... + 9995485478.

Almost surely, 2^39981941906 is an apocalyptic number.

39981941906 is a deficient number, since it is larger than the sum of its proper divisors (19990970956).

39981941906 is a wasteful number, since it uses less digits than its factorization.

39981941906 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19990970955.

The product of its (nonzero) digits is 3779136, while the sum is 59.

The spelling of 39981941906 in words is "thirty-nine billion, nine hundred eighty-one million, nine hundred forty-one thousand, nine hundred six".