2220120021221 has 4 divisors (see below), whose sum is σ = 2220608071500. Its totient is φ = 2219631970944.

The previous prime is 2220120021209. The next prime is 2220120021247. The reversal of 2220120021221 is 1221200210222.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 705709204225 + 1514410816996 = 840065^2 + 1230614^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2220120021221 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 2220120021221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2220129021221) 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, 244018316 + ... + 244027413.

It is an arithmetic number, because the mean of its divisors is an integer number (555152017875).

Almost surely, 2^{2220120021221} is an apocalyptic number.

It is an amenable number.

2220120021221 is a deficient number, since it is larger than the sum of its proper divisors (488050279).

2220120021221 is an equidigital number, since it uses as much as digits as its factorization.

2220120021221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 488050278.

The product of its (nonzero) digits is 128, while the sum is 17.

Adding to 2220120021221 its reverse (1221200210222), we get a palindrome (3441320231443).

The spelling of 2220120021221 in words is "two trillion, two hundred twenty billion, one hundred twenty million, twenty-one thousand, two hundred twenty-one".