1211111112101 has 4 divisors (see below), whose sum is σ = 1321212122304. Its totient is φ = 1101010101900.

The previous prime is 1211111112019. The next prime is 1211111112131. The reversal of 1211111112101 is 1012111111121.

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 1211111112101 - 2¹⁸ = 1211110849957 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 (1211111112131) 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, 55050505085 + ... + 55050505106.

It is an arithmetic number, because the mean of its divisors is an integer number (330303030576).

Almost surely, 2^{1211111112101} is an apocalyptic number.

1211111112101 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1211111112101 is a deficient number, since it is larger than the sum of its proper divisors (110101010203).

1211111112101 is a wasteful number, since it uses less digits than its factorization.

1211111112101 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 110101010202.

The product of its (nonzero) digits is 4, while the sum is 14.

Adding to 1211111112101 its reverse (1012111111121), we get a palindrome (2223222223222).

The spelling of 1211111112101 in words is "one trillion, two hundred eleven billion, one hundred eleven million, one hundred twelve thousand, one hundred one".