1221220101011 has 4 divisors (see below), whose sum is σ = 1222093026000. Its totient is φ = 1220347176024.

The previous prime is 1221220101007. The next prime is 1221220101083. The reversal of 1221220101011 is 1101010221221.

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

It is a cyclic number.

It is not a de Polignac number, because 1221220101011 - 2² = 1221220101007 is a prime.

It is a super-2 number, since 2×1221220101011² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1221220101811) 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, 436460396 + ... + 436463193.

It is an arithmetic number, because the mean of its divisors is an integer number (305523256500).

Almost surely, 2^{1221220101011} is an apocalyptic number.

1221220101011 is a deficient number, since it is larger than the sum of its proper divisors (872924989).

1221220101011 is an equidigital number, since it uses as much as digits as its factorization.

1221220101011 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 872924988.

The product of its (nonzero) digits is 16, while the sum is 14.

Adding to 1221220101011 its reverse (1101010221221), we get a palindrome (2322230322232).

It can be divided in two parts, 1221220 and 101011, that added together give a palindrome (1322231).

The spelling of 1221220101011 in words is "one trillion, two hundred twenty-one billion, two hundred twenty million, one hundred one thousand, eleven".