1221012112011 has 32 divisors (see below), whose sum is σ = 1823909034240. Its totient is φ = 722042118144.

The previous prime is 1221012112009. The next prime is 1221012112031. The reversal of 1221012112011 is 1102112101221.

It is a happy number.

It is not a de Polignac number, because 1221012112011 - 2¹ = 1221012112009 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1221012112031) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3077425 + ... + 3451458.

It is an arithmetic number, because the mean of its divisors is an integer number (56997157320).

Almost surely, 2^{1221012112011} is an apocalyptic number.

1221012112011 is a deficient number, since it is larger than the sum of its proper divisors (602896922229).

1221012112011 is a wasteful number, since it uses less digits than its factorization.

1221012112011 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6529115.

The product of its (nonzero) digits is 16, while the sum is 15.

Adding to 1221012112011 its reverse (1102112101221), we get a palindrome (2323124213232).

The spelling of 1221012112011 in words is "one trillion, two hundred twenty-one billion, twelve million, one hundred twelve thousand, eleven".