1021211111091 has 16 divisors (see below), whose sum is σ = 1366050644640. Its totient is φ = 678589766400.

The previous prime is 1021211111087. The next prime is 1021211111113. The reversal of 1021211111091 is 1901111121201.

It is a happy number.

It is not a de Polignac number, because 1021211111091 - 2² = 1021211111087 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1021211111071) 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, 23894041 + ... + 23936741.

It is an arithmetic number, because the mean of its divisors is an integer number (85378165290).

Almost surely, 2^{1021211111091} is an apocalyptic number.

1021211111091 is a deficient number, since it is larger than the sum of its proper divisors (344839533549).

1021211111091 is a wasteful number, since it uses less digits than its factorization.

1021211111091 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 68486.

The product of its (nonzero) digits is 36, while the sum is 21.

Adding to 1021211111091 its reverse (1901111121201), we get a palindrome (2922322232292).

The spelling of 1021211111091 in words is "one trillion, twenty-one billion, two hundred eleven million, one hundred eleven thousand, ninety-one".