6628171881 has 4 divisors (see below), whose sum is σ = 8837562512. Its totient is φ = 4418781252.

The previous prime is 6628171877. The next prime is 6628171883. The reversal of 6628171881 is 1881718266.

It is a happy number.

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 not a de Polignac number, because 6628171881 - 2² = 6628171877 is a prime.

It is a super-2 number, since 2×6628171881² = 87865324968158156322, which contains 22 as substring.

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 6628171881.

It is not an unprimeable number, because it can be changed into a prime (6628171883) 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, 1104695311 + ... + 1104695316.

It is an arithmetic number, because the mean of its divisors is an integer number (2209390628).

Almost surely, 2^6628171881 is an apocalyptic number.

It is an amenable number.

6628171881 is a deficient number, since it is larger than the sum of its proper divisors (2209390631).

6628171881 is a wasteful number, since it uses less digits than its factorization.

6628171881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2209390630.

The product of its digits is 258048, while the sum is 48.

The square root of 6628171881 is about 81413.5853589559. The cubic root of 6628171881 is about 1878.4425649211.

The spelling of 6628171881 in words is "six billion, six hundred twenty-eight million, one hundred seventy-one thousand, eight hundred eighty-one".