6446421 has 12 divisors (see below), whose sum is σ = 9348300. Its totient is φ = 4280640.

The previous prime is 6446413. The next prime is 6446437. The reversal of 6446421 is 1246446.

It can be written as a sum of positive squares in 2 ways, for example, as 5267025 + 1179396 = 2295^2 + 1086^2 .

It is not a de Polignac number, because 6446421 - 2³ = 6446413 is a prime.

It is a Curzon number.

6446421 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6446021) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1255 + ... + 3803.

It is an arithmetic number, because the mean of its divisors is an integer number (779025).

Almost surely, 2^6446421 is an apocalyptic number.

It is an amenable number.

6446421 is a deficient number, since it is larger than the sum of its proper divisors (2901879).

6446421 is a wasteful number, since it uses less digits than its factorization.

6446421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2836 (or 2833 counting only the distinct ones).

The product of its digits is 4608, while the sum is 27.

The square root of 6446421 is about 2538.9803071312. The cubic root of 6446421 is about 186.1113623785. Note that the first 3 decimals are identical.

The spelling of 6446421 in words is "six million, four hundred forty-six thousand, four hundred twenty-one".