221920129 has 8 divisors (see below), whose sum is σ = 224765568. Its totient is φ = 219087600.

The previous prime is 221920087. The next prime is 221920141. The reversal of 221920129 is 921029122.

221920129 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 221920129 - 2⁷ = 221920001 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 221920097 and 221920106.

It is not an unprimeable number, because it can be changed into a prime (221920199) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 34074 + ... + 40060.

It is an arithmetic number, because the mean of its divisors is an integer number (28095696).

Almost surely, 2^221920129 is an apocalyptic number.

It is an amenable number.

221920129 is a deficient number, since it is larger than the sum of its proper divisors (2845439).

221920129 is a wasteful number, since it uses less digits than its factorization.

221920129 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6455.

The product of its (nonzero) digits is 1296, while the sum is 28.

The square root of 221920129 is about 14896.9838893650. The cubic root of 221920129 is about 605.4322699026.

The spelling of 221920129 in words is "two hundred twenty-one million, nine hundred twenty thousand, one hundred twenty-nine".