6442904421 has 12 divisors (see below), whose sum is σ = 9308353548. Its totient is φ = 4294376064.

The previous prime is 6442904399. The next prime is 6442904449. The reversal of 6442904421 is 1244092446.

It is a happy number.

6442904421 is a `hidden beast` number, since 644 + 2 + 9 + 0 + 4 + 4 + 2 + 1 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 1729395396 + 4713509025 = 41586^2 + 68655^2 .

It is not a de Polignac number, because 6442904421 - 2¹⁵ = 6442871653 is a prime.

It is a super-2 number, since 2×6442904421² = 83022034756282690482, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6442924421) 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, 27220 + ... + 116733.

It is an arithmetic number, because the mean of its divisors is an integer number (775696129).

Almost surely, 2^6442904421 is an apocalyptic number.

It is an amenable number.

6442904421 is a deficient number, since it is larger than the sum of its proper divisors (2865449127).

6442904421 is a wasteful number, since it uses less digits than its factorization.

6442904421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 148932 (or 148929 counting only the distinct ones).

The product of its (nonzero) digits is 55296, while the sum is 36.

The square root of 6442904421 is about 80267.7047198934. The cubic root of 6442904421 is about 1860.7751443133.

Adding to 6442904421 its reverse (1244092446), we get a palindrome (7686996867).

The spelling of 6442904421 in words is "six billion, four hundred forty-two million, nine hundred four thousand, four hundred twenty-one".