39742981 has 4 divisors (see below), whose sum is σ = 40712364. Its totient is φ = 38773600.

The previous prime is 39742949. The next prime is 39743017. The reversal of 39742981 is 18924793.

39742981 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It can be written as a sum of positive squares in 2 ways, for example, as 7650756 + 32092225 = 2766^2 + 5665^2 .

It is a cyclic number.

It is not a de Polignac number, because 39742981 - 2⁵ = 39742949 is a prime.

It is a super-2 number, since 2×39742981² = 3159009077532722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (39742081) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 484630 + ... + 484711.

It is an arithmetic number, because the mean of its divisors is an integer number (10178091).

Almost surely, 2^39742981 is an apocalyptic number.

It is an amenable number.

39742981 is a deficient number, since it is larger than the sum of its proper divisors (969383).

39742981 is an equidigital number, since it uses as much as digits as its factorization.

39742981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 969382.

The product of its digits is 108864, while the sum is 43.

The square root of 39742981 is about 6304.2034389763. The cubic root of 39742981 is about 341.2611209908.

The spelling of 39742981 in words is "thirty-nine million, seven hundred forty-two thousand, nine hundred eighty-one".