1211011111001 has 8 divisors (see below), whose sum is σ = 1219165992000. Its totient is φ = 1202856594160.

The previous prime is 1211011110961. The next prime is 1211011111007. The reversal of 1211011111001 is 1001111101121.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1211011111001 - 2³⁰ = 1209937369177 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1211011111007) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11695466 + ... + 11798556.

It is an arithmetic number, because the mean of its divisors is an integer number (152395749000).

Almost surely, 2^{1211011111001} is an apocalyptic number.

It is an amenable number.

1211011111001 is a deficient number, since it is larger than the sum of its proper divisors (8154880999).

1211011111001 is a wasteful number, since it uses less digits than its factorization.

1211011111001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 182079.

The product of its (nonzero) digits is 2, while the sum is 11.

Adding to 1211011111001 its reverse (1001111101121), we get a palindrome (2212122212122).

The spelling of 1211011111001 in words is "one trillion, two hundred eleven billion, eleven million, one hundred eleven thousand, one".