6442637641421 has 4 divisors (see below), whose sum is σ = 6650464662144. Its totient is φ = 6234810620700.

The previous prime is 6442637641411. The next prime is 6442637641439. The reversal of 6442637641421 is 1241467362446.

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.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-6442637641421 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 6442637641421.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6442637641411) 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, 103913510315 + ... + 103913510376.

It is an arithmetic number, because the mean of its divisors is an integer number (1662616165536).

Almost surely, 2^{6442637641421} is an apocalyptic number.

It is an amenable number.

6442637641421 is a deficient number, since it is larger than the sum of its proper divisors (207827020723).

6442637641421 is a wasteful number, since it uses less digits than its factorization.

6442637641421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 207827020722.

The product of its digits is 4644864, while the sum is 50.

The spelling of 6442637641421 in words is "six trillion, four hundred forty-two billion, six hundred thirty-seven million, six hundred forty-one thousand, four hundred twenty-one".