39428809 has 4 divisors (see below), whose sum is σ = 45061504. Its totient is φ = 33796116.

The previous prime is 39428783. The next prime is 39428813. The reversal of 39428809 is 90882493.

It is a happy number.

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.

It is a cyclic number.

It is not a de Polignac number, because 39428809 - 2⁷ = 39428681 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (39428209) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2816337 + ... + 2816350.

It is an arithmetic number, because the mean of its divisors is an integer number (11265376).

Almost surely, 2^39428809 is an apocalyptic number.

It is an amenable number.

39428809 is a deficient number, since it is larger than the sum of its proper divisors (5632695).

39428809 is an equidigital number, since it uses as much as digits as its factorization.

39428809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5632694.

The product of its (nonzero) digits is 124416, while the sum is 43.

The square root of 39428809 is about 6279.2363389189. The cubic root of 39428809 is about 340.3595072755.

The spelling of 39428809 in words is "thirty-nine million, four hundred twenty-eight thousand, eight hundred nine".