221999977 has 4 divisors (see below), whose sum is σ = 222051456. Its totient is φ = 221948500.

The previous prime is 221999929. The next prime is 221999983. The reversal of 221999977 is 779999122.

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 a cyclic number.

It is not a de Polignac number, because 221999977 - 2⁷ = 221999849 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (221999077) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 18613 + ... + 28114.

It is an arithmetic number, because the mean of its divisors is an integer number (55512864).

Almost surely, 2^221999977 is an apocalyptic number.

It is an amenable number.

221999977 is a deficient number, since it is larger than the sum of its proper divisors (51479).

221999977 is an equidigital number, since it uses as much as digits as its factorization.

221999977 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 51478.

The product of its digits is 1285956, while the sum is 55.

The square root of 221999977 is about 14899.6636539219. The cubic root of 221999977 is about 605.5048737403.

The spelling of 221999977 in words is "two hundred twenty-one million, nine hundred ninety-nine thousand, nine hundred seventy-seven".