16271666721 has 32 divisors (see below), whose sum is σ = 24369966720. Its totient is φ = 10729720512.

The previous prime is 16271666717. The next prime is 16271666777. The reversal of 16271666721 is 12766617261.

It is not a de Polignac number, because 16271666721 - 2² = 16271666717 is a prime.

It is not an unprimeable number, because it can be changed into a prime (16271666701) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 911346 + ... + 929028.

It is an arithmetic number, because the mean of its divisors is an integer number (761561460).

Almost surely, 2^16271666721 is an apocalyptic number.

It is an amenable number.

16271666721 is a deficient number, since it is larger than the sum of its proper divisors (8098299999).

16271666721 is a wasteful number, since it uses less digits than its factorization.

16271666721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18062 (or 18056 counting only the distinct ones).

The product of its digits is 254016, while the sum is 45.

The spelling of 16271666721 in words is "sixteen billion, two hundred seventy-one million, six hundred sixty-six thousand, seven hundred twenty-one".