127221666 has 64 divisors (see below), whose sum is σ = 309294720. Its totient is φ = 34352640.

The previous prime is 127221631. The next prime is 127221683. The reversal of 127221666 is 666122721.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 22326 + ... + 27438.

It is an arithmetic number, because the mean of its divisors is an integer number (4832730).

Almost surely, 2^127221666 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 127221666, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (154647360).

127221666 is an abundant number, since it is smaller than the sum of its proper divisors (182073054).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

127221666 is a wasteful number, since it uses less digits than its factorization.

127221666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5171.

The product of its digits is 12096, while the sum is 33.

The square root of 127221666 is about 11279.2582202909. The cubic root of 127221666 is about 502.9448430812.

The spelling of 127221666 in words is "one hundred twenty-seven million, two hundred twenty-one thousand, six hundred sixty-six".