6442075621 has 4 divisors (see below), whose sum is σ = 6649884544. Its totient is φ = 6234266700.

The previous prime is 6442075613. The next prime is 6442075663. The reversal of 6442075621 is 1265702446.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1265702446 = 2 ⋅632851223.

It is a cyclic number.

It is not a de Polignac number, because 6442075621 - 2³ = 6442075613 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 (6442075721) 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, 103904415 + ... + 103904476.

It is an arithmetic number, because the mean of its divisors is an integer number (1662471136).

Almost surely, 2^6442075621 is an apocalyptic number.

It is an amenable number.

6442075621 is a deficient number, since it is larger than the sum of its proper divisors (207808923).

6442075621 is a wasteful number, since it uses less digits than its factorization.

6442075621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 207808922.

The product of its (nonzero) digits is 80640, while the sum is 37.

The square root of 6442075621 is about 80262.5418299221. The cubic root of 6442075621 is about 1860.6953523192.

It can be divided in two parts, 64420 and 75621, that added together give a palindrome (140041).

The spelling of 6442075621 in words is "six billion, four hundred forty-two million, seventy-five thousand, six hundred twenty-one".