6445139 has 4 divisors (see below), whose sum is σ = 6452856. Its totient is φ = 6437424.

The previous prime is 6445099. The next prime is 6445147. The reversal of 6445139 is 9315446.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 6445139 - 2²⁰ = 5396563 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6445169) 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, 2429 + ... + 4334.

It is an arithmetic number, because the mean of its divisors is an integer number (1613214).

Almost surely, 2^6445139 is an apocalyptic number.

6445139 is a deficient number, since it is larger than the sum of its proper divisors (7717).

6445139 is an equidigital number, since it uses as much as digits as its factorization.

6445139 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7716.

The product of its digits is 12960, while the sum is 32.

The square root of 6445139 is about 2538.7278310209. The cubic root of 6445139 is about 186.0990242359.

The spelling of 6445139 in words is "six million, four hundred forty-five thousand, one hundred thirty-nine".