6445621255 has 8 divisors (see below), whose sum is σ = 7735743792. Its totient is φ = 5155831488.

The previous prime is 6445621253. The next prime is 6445621261. The reversal of 6445621255 is 5521265446.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 6445621255 - 2¹ = 6445621253 is a prime.

It is a Duffinian number.

It is a zygodrome in base 2.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6445621253) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 38382 + ... + 119851.

It is an arithmetic number, because the mean of its divisors is an integer number (966967974).

Almost surely, 2^6445621255 is an apocalyptic number.

6445621255 is a deficient number, since it is larger than the sum of its proper divisors (1290122537).

6445621255 is a wasteful number, since it uses less digits than its factorization.

6445621255 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 166385.

The product of its digits is 288000, while the sum is 40.

The square root of 6445621255 is about 80284.6265171608. The cubic root of 6445621255 is about 1861.0366571563.

The spelling of 6445621255 in words is "six billion, four hundred forty-five million, six hundred twenty-one thousand, two hundred fifty-five".