1231221213101 has 16 divisors (see below), whose sum is σ = 1413885249600. Its totient is φ = 1060349875200.

The previous prime is 1231221213073. The next prime is 1231221213107. The reversal of 1231221213101 is 1013121221321.

It is a de Polignac number, because none of the positive numbers 2^k-1231221213101 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1231221213107) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9122531 + ... + 9256511.

It is an arithmetic number, because the mean of its divisors is an integer number (88367828100).

Almost surely, 2^{1231221213101} is an apocalyptic number.

1231221213101 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1231221213101 is a deficient number, since it is larger than the sum of its proper divisors (182664036499).

1231221213101 is a wasteful number, since it uses less digits than its factorization.

1231221213101 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 177980.

The product of its (nonzero) digits is 144, while the sum is 20.

Adding to 1231221213101 its reverse (1013121221321), we get a palindrome (2244342434422).

The spelling of 1231221213101 in words is "one trillion, two hundred thirty-one billion, two hundred twenty-one million, two hundred thirteen thousand, one hundred one".