1211991664226 has 8 divisors (see below), whose sum is σ = 2077699995840. Its totient is φ = 519424998948.

The previous prime is 1211991664211. The next prime is 1211991664243. The reversal of 1211991664226 is 6224661991121.

It is a happy number.

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

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 43285416566 + ... + 43285416593.

It is an arithmetic number, because the mean of its divisors is an integer number (259712499480).

Almost surely, 2^{1211991664226} is an apocalyptic number.

1211991664226 is a deficient number, since it is larger than the sum of its proper divisors (865708331614).

1211991664226 is an equidigital number, since it uses as much as digits as its factorization.

1211991664226 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 86570833168.

The product of its digits is 559872, while the sum is 50.

The spelling of 1211991664226 in words is "one trillion, two hundred eleven billion, nine hundred ninety-one million, six hundred sixty-four thousand, two hundred twenty-six".