221420129 has 16 divisors (see below), whose sum is σ = 268876800. Its totient is φ = 178107984.

The previous prime is 221420119. The next prime is 221420137. The reversal of 221420129 is 921024122.

It is a cyclic number.

It is not a de Polignac number, because 221420129 - 2²⁰ = 220371553 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (221420119) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6452 + ... + 22010.

It is an arithmetic number, because the mean of its divisors is an integer number (16804800).

Almost surely, 2^221420129 is an apocalyptic number.

It is an amenable number.

221420129 is a deficient number, since it is larger than the sum of its proper divisors (47456671).

221420129 is a wasteful number, since it uses less digits than its factorization.

221420129 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15692.

The product of its (nonzero) digits is 576, while the sum is 23.

The square root of 221420129 is about 14880.1925054752. The cubic root of 221420129 is about 604.9772356710.

The spelling of 221420129 in words is "two hundred twenty-one million, four hundred twenty thousand, one hundred twenty-nine".