221130021 has 16 divisors (see below), whose sum is σ = 337250304. Its totient is φ = 126251184.

The previous prime is 221130001. The next prime is 221130031. The reversal of 221130021 is 120031122.

221130021 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 221130021 - 2⁵ = 221129989 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 221129979 and 221130006.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221130001) 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, 24856 + ... + 32558.

It is an arithmetic number, because the mean of its divisors is an integer number (21078144).

Almost surely, 2^221130021 is an apocalyptic number.

221130021 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

221130021 is a deficient number, since it is larger than the sum of its proper divisors (116120283).

221130021 is a wasteful number, since it uses less digits than its factorization.

221130021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9080.

The product of its (nonzero) digits is 24, while the sum is 12.

The square root of 221130021 is about 14870.4411837712. The cubic root of 221130021 is about 604.7129034203.

Adding to 221130021 its reverse (120031122), we get a palindrome (341161143).

The spelling of 221130021 in words is "two hundred twenty-one million, one hundred thirty thousand, twenty-one".