39240821 has 2 divisors, whose sum is σ = 39240822. Its totient is φ = 39240820.

The previous prime is 39240797. The next prime is 39240827. The reversal of 39240821 is 12804293.

39240821 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 25654225 + 13586596 = 5065^2 + 3686^2 .

It is an emirp because it is prime and its reverse (12804293) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 39240821 - 2¹⁰ = 39239797 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (39240827) 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 as a sum of consecutive naturals, namely, 19620410 + 19620411.

It is an arithmetic number, because the mean of its divisors is an integer number (19620411).

Almost surely, 2^39240821 is an apocalyptic number.

It is an amenable number.

39240821 is a deficient number, since it is larger than the sum of its proper divisors (1).

39240821 is an equidigital number, since it uses as much as digits as its factorization.

39240821 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3456, while the sum is 29.

The square root of 39240821 is about 6264.2494362852. The cubic root of 39240821 is about 339.8177252523.

The spelling of 39240821 in words is "thirty-nine million, two hundred forty thousand, eight hundred twenty-one".