221421255546666 has 64 divisors (see below), whose sum is σ = 528305313795840. Its totient is φ = 60544327080960.

The previous prime is 221421255546649. The next prime is 221421255546679. The reversal of 221421255546666 is 666645552124122.

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, 1167812751 + ... + 1168002338.

It is an arithmetic number, because the mean of its divisors is an integer number (8254770528060).

Almost surely, 2^{221421255546666} is an apocalyptic number.

221421255546666 is an abundant number, since it is smaller than the sum of its proper divisors (306884058249174).

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

221421255546666 is a wasteful number, since it uses less digits than its factorization.

221421255546666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2335815199.

The product of its digits is 41472000, while the sum is 57.

The spelling of 221421255546666 in words is "two hundred twenty-one trillion, four hundred twenty-one billion, two hundred fifty-five million, five hundred forty-six thousand, six hundred sixty-six".