6642557071 has 4 divisors (see below), whose sum is σ = 6643335672. Its totient is φ = 6641778472.

The previous prime is 6642557063. The next prime is 6642557087. The reversal of 6642557071 is 1707552466.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 6642557071 - 2³ = 6642557063 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 (6642557171) 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, 376360 + ... + 393613.

It is an arithmetic number, because the mean of its divisors is an integer number (1660833918).

Almost surely, 2^6642557071 is an apocalyptic number.

6642557071 is a deficient number, since it is larger than the sum of its proper divisors (778601).

6642557071 is an equidigital number, since it uses as much as digits as its factorization.

6642557071 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 778600.

The product of its (nonzero) digits is 352800, while the sum is 43.

The square root of 6642557071 is about 81501.8838493933. The cubic root of 6642557071 is about 1879.8005174451.

The spelling of 6642557071 in words is "six billion, six hundred forty-two million, five hundred fifty-seven thousand, seventy-one".