1221110191 has 8 divisors (see below), whose sum is σ = 1400488064. Its totient is φ = 1042965720.

The previous prime is 1221110161. The next prime is 1221110237. The reversal of 1221110191 is 1910111221.

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 1221110191 - 2⁵ = 1221110159 is a prime.

It is a super-2 number, since 2×1221110191² = 2982220197128112962, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221110101) 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, 306225 + ... + 310186.

It is an arithmetic number, because the mean of its divisors is an integer number (175061008).

Almost surely, 2^1221110191 is an apocalyptic number.

1221110191 is a deficient number, since it is larger than the sum of its proper divisors (179377873).

1221110191 is an equidigital number, since it uses as much as digits as its factorization.

1221110191 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 616701.

The product of its (nonzero) digits is 36, while the sum is 19.

The square root of 1221110191 is about 34944.3871172467. The cubic root of 1221110191 is about 1068.8537499408.

The spelling of 1221110191 in words is "one billion, two hundred twenty-one million, one hundred ten thousand, one hundred ninety-one".