6446389 has 4 divisors (see below), whose sum is σ = 6603660. Its totient is φ = 6289120.

The previous prime is 6446387. The next prime is 6446413. The reversal of 6446389 is 9836446.

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

It can be written as a sum of positive squares in 2 ways, for example, as 483025 + 5963364 = 695^2 + 2442^2 .

It is a cyclic number.

It is not a de Polignac number, because 6446389 - 2¹ = 6446387 is a prime.

It is a super-2 number, since 2×6446389² = 83111862278642, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6446387) 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, 78574 + ... + 78655.

It is an arithmetic number, because the mean of its divisors is an integer number (1650915).

Almost surely, 2^6446389 is an apocalyptic number.

It is an amenable number.

6446389 is a deficient number, since it is larger than the sum of its proper divisors (157271).

6446389 is a wasteful number, since it uses less digits than its factorization.

6446389 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 157270.

The product of its digits is 124416, while the sum is 40.

The square root of 6446389 is about 2538.9740053809. The cubic root of 6446389 is about 186.1110544260. Note that the first 3 decimals are identical.

The spelling of 6446389 in words is "six million, four hundred forty-six thousand, three hundred eighty-nine".