39828721 has 3 divisors (see below), whose sum is σ = 39835033. Its totient is φ = 39822410.

The previous prime is 39828713. The next prime is 39828749. The reversal of 39828721 is 12782893.

The square root of 39828721 is 6311.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is not a de Polignac number, because 39828721 - 2³ = 39828713 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (39828751) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 3156 + ... + 9466.

Almost surely, 2^39828721 is an apocalyptic number.

39828721 is the 6311-st square number.

39828721 is the 3156-th centered octagonal number.

It is an amenable number.

39828721 is a deficient number, since it is larger than the sum of its proper divisors (6312).

39828721 is an frugal number, since it uses more digits than its factorization.

39828721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12622 (or 6311 counting only the distinct ones).

The product of its digits is 48384, while the sum is 40.

The cubic root of 39828721 is about 341.5063526576.

The spelling of 39828721 in words is "thirty-nine million, eight hundred twenty-eight thousand, seven hundred twenty-one".