221129999 has 16 divisors (see below), whose sum is σ = 247276800. Its totient is φ = 196516224.

The previous prime is 221129989. The next prime is 221130001. The reversal of 221129999 is 999921122.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 221129999 - 2⁴ = 221129983 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221129989) 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, 115004 + ... + 116910.

It is an arithmetic number, because the mean of its divisors is an integer number (15454800).

Almost surely, 2^221129999 is an apocalyptic number.

221129999 is a deficient number, since it is larger than the sum of its proper divisors (26146801).

221129999 is a wasteful number, since it uses less digits than its factorization.

221129999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2302.

The product of its digits is 52488, while the sum is 44.

The square root of 221129999 is about 14870.4404440487. The cubic root of 221129999 is about 604.7128833663.

The spelling of 221129999 in words is "two hundred twenty-one million, one hundred twenty-nine thousand, nine hundred ninety-nine".