6421447 has 4 divisors (see below), whose sum is σ = 6427696. Its totient is φ = 6415200.

The previous prime is 6421421. The next prime is 6421477. The reversal of 6421447 is 7441246.

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, and also an emirpimes, since its reverse is a distinct semiprime: 7441246 = 2 ⋅3720623.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-6421447 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 (6421417) 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, 1179 + ... + 3772.

It is an arithmetic number, because the mean of its divisors is an integer number (1606924).

Almost surely, 2^6421447 is an apocalyptic number.

6421447 is a deficient number, since it is larger than the sum of its proper divisors (6249).

6421447 is a wasteful number, since it uses less digits than its factorization.

6421447 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6248.

The product of its digits is 5376, while the sum is 28.

The square root of 6421447 is about 2534.0574184497. The cubic root of 6421447 is about 185.8707141026.

It can be divided in two parts, 64214 and 47, that added together give a triangular number (64261 = T₃₅₈).

The spelling of 6421447 in words is "six million, four hundred twenty-one thousand, four hundred forty-seven".