2211220021 has 4 divisors (see below), whose sum is σ = 2224785952. Its totient is φ = 2197654092.

The previous prime is 2211220007. The next prime is 2211220031. The reversal of 2211220021 is 1200221122.

It is a happy number.

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: 1200221122 = 2 ⋅600110561.

It is a cyclic number.

It is not a de Polignac number, because 2211220021 - 2⁹ = 2211219509 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2211219983 and 2211220010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2211220001) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6782721 + ... + 6783046.

It is an arithmetic number, because the mean of its divisors is an integer number (556196488).

Almost surely, 2^2211220021 is an apocalyptic number.

It is an amenable number.

2211220021 is a deficient number, since it is larger than the sum of its proper divisors (13565931).

2211220021 is a wasteful number, since it uses less digits than its factorization.

2211220021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13565930.

The product of its (nonzero) digits is 32, while the sum is 13.

The square root of 2211220021 is about 47023.6113138921. The cubic root of 2211220021 is about 1302.7987083396.

Adding to 2211220021 its reverse (1200221122), we get a palindrome (3411441143).

The spelling of 2211220021 in words is "two billion, two hundred eleven million, two hundred twenty thousand, twenty-one".