6388221971 has 16 divisors (see below), whose sum is σ = 7123404960. Its totient is φ = 5693276160.

The previous prime is 6388221967. The next prime is 6388221979. The reversal of 6388221971 is 1791228836.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 6388221971 - 2² = 6388221967 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6388221979) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1004915 + ... + 1011251.

It is an arithmetic number, because the mean of its divisors is an integer number (445212810).

Almost surely, 2^6388221971 is an apocalyptic number.

6388221971 is a deficient number, since it is larger than the sum of its proper divisors (735182989).

6388221971 is a wasteful number, since it uses less digits than its factorization.

6388221971 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9494.

The product of its digits is 290304, while the sum is 47.

The square root of 6388221971 is about 79926.3534198827. The cubic root of 6388221971 is about 1855.4959013999.

The spelling of 6388221971 in words is "six billion, three hundred eighty-eight million, two hundred twenty-one thousand, nine hundred seventy-one".