1211901992121 has 8 divisors (see below), whose sum is σ = 1618669791904. Its totient is φ = 806534426880.

The previous prime is 1211901992113. The next prime is 1211901992141. The reversal of 1211901992121 is 1212991091121.

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

It is not a de Polignac number, because 1211901992121 - 2³ = 1211901992113 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 1211901992121.

It is not an unprimeable number, because it can be changed into a prime (1211901992141) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 350056615 + ... + 350060076.

It is an arithmetic number, because the mean of its divisors is an integer number (202333723988).

Almost surely, 2^{1211901992121} is an apocalyptic number.

It is an amenable number.

1211901992121 is a deficient number, since it is larger than the sum of its proper divisors (406767799783).

1211901992121 is an equidigital number, since it uses as much as digits as its factorization.

1211901992121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 700117271.

The product of its (nonzero) digits is 5832, while the sum is 39.

It can be divided in two parts, 1211901 and 992121, that added together give a palindrome (2204022).

The spelling of 1211901992121 in words is "one trillion, two hundred eleven billion, nine hundred one million, nine hundred ninety-two thousand, one hundred twenty-one".