221422021 has 4 divisors (see below), whose sum is σ = 222888544. Its totient is φ = 219955500.

The previous prime is 221422013. The next prime is 221422037. The reversal of 221422021 is 120224122.

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, and also an emirpimes, since its reverse is a distinct semiprime: 120224122 = 2 ⋅60112061.

It is a cyclic number.

It is not a de Polignac number, because 221422021 - 2³ = 221422013 is a prime.

It is a super-2 number, since 2×221422021² = 98055422767448882, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 221421986 and 221422004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221422001) 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 3 ways as a sum of consecutive naturals, for example, 733035 + ... + 733336.

It is an arithmetic number, because the mean of its divisors is an integer number (55722136).

Almost surely, 2^221422021 is an apocalyptic number.

It is an amenable number.

221422021 is a deficient number, since it is larger than the sum of its proper divisors (1466523).

221422021 is a wasteful number, since it uses less digits than its factorization.

221422021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1466522.

The product of its (nonzero) digits is 128, while the sum is 16.

The square root of 221422021 is about 14880.2560797857. The cubic root of 221422021 is about 604.9789588111.

Adding to 221422021 its reverse (120224122), we get a palindrome (341646143).

The spelling of 221422021 in words is "two hundred twenty-one million, four hundred twenty-two thousand, twenty-one".