39457021 has 4 divisors (see below), whose sum is σ = 39469852. Its totient is φ = 39444192.

The previous prime is 39457009. The next prime is 39457027. The reversal of 39457021 is 12075493.

39457021 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, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 7080921 + 32376100 = 2661^2 + 5690^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-39457021 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (39457027) 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, 1255 + ... + 8971.

It is an arithmetic number, because the mean of its divisors is an integer number (9867463).

Almost surely, 2^39457021 is an apocalyptic number.

It is an amenable number.

39457021 is a deficient number, since it is larger than the sum of its proper divisors (12831).

39457021 is an equidigital number, since it uses as much as digits as its factorization.

39457021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12830.

The product of its (nonzero) digits is 7560, while the sum is 31.

The square root of 39457021 is about 6281.4823887360. The cubic root of 39457021 is about 340.4406656416.

The spelling of 39457021 in words is "thirty-nine million, four hundred fifty-seven thousand, twenty-one".