39490021 has 4 divisors (see below), whose sum is σ = 39521632. Its totient is φ = 39458412.

The previous prime is 39489991. The next prime is 39490049. The reversal of 39490021 is 12009493.

It is a happy number.

39490021 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 Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 12009493 = 31 ⋅387403.

It is a cyclic number.

It is not a de Polignac number, because 39490021 - 2⁷ = 39489893 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 (39490051) 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, 13851 + ... + 16456.

It is an arithmetic number, because the mean of its divisors is an integer number (9880408).

Almost surely, 2^39490021 is an apocalyptic number.

It is an amenable number.

39490021 is a deficient number, since it is larger than the sum of its proper divisors (31611).

39490021 is a wasteful number, since it uses less digits than its factorization.

39490021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31610.

The product of its (nonzero) digits is 1944, while the sum is 28.

The square root of 39490021 is about 6284.1086082276. The cubic root of 39490021 is about 340.5355487247.

The spelling of 39490021 in words is "thirty-nine million, four hundred ninety thousand, twenty-one".