1220211110021 has 4 divisors (see below), whose sum is σ = 1221835892544.
Its totient is φ = 1218586327500.
The previous prime is 1220211110009. The next prime is 1220211110029. The reversal of 1220211110021 is 1200111120221.
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.
It is a cyclic number.
It is not a de Polignac number, because 1220211110021 - 214 = 1220211093637 is a prime.
It is a Duffinian number.
It is a Curzon number.
It is a junction number, because it is equal to n+sod(n) for n = 1220211109978 and 1220211110005.
It is a congruent number.
It is not an unprimeable number, because it can be changed into a prime (1220211110029) 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, 812390135 + ... + 812391636.
It is an arithmetic number, because the mean of its divisors is an integer number (305458973136).
Almost surely, 21220211110021 is an apocalyptic number.
It is an amenable number.
1220211110021 is a deficient number, since it is larger than the sum of its proper divisors (1624782523).
1220211110021 is an equidigital number, since it uses as much as digits as its factorization.
1220211110021 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 1624782522.
The product of its (nonzero) digits is 16, while the sum is 14.
Adding to 1220211110021 its reverse (1200111120221), we get a palindrome (2420322230242).
The spelling of 1220211110021 in words is "one trillion, two hundred twenty billion, two hundred eleven million, one hundred ten thousand, twenty-one".