991211202012111 has 16 divisors (see below), whose sum is σ = 1323792465193824. Its totient is φ = 659718760909824.

The previous prime is 991211202012089. The next prime is 991211202012131. The reversal of 991211202012111 is 111210202112199.

It is not a de Polignac number, because 991211202012111 - 2⁷ = 991211202011983 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (991211202012131) 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, 61980471 + ... + 76315143.

It is an arithmetic number, because the mean of its divisors is an integer number (82737029074614).

Almost surely, 2^{991211202012111} is an apocalyptic number.

991211202012111 is a deficient number, since it is larger than the sum of its proper divisors (332581263181713).

991211202012111 is a wasteful number, since it uses less digits than its factorization.

991211202012111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14372650.

The product of its (nonzero) digits is 1296, while the sum is 33.

The spelling of 991211202012111 in words is "nine hundred ninety-one trillion, two hundred eleven billion, two hundred two million, twelve thousand, one hundred eleven".