1122001991 has 8 divisors (see below), whose sum is σ = 1229126400. Its totient is φ = 1015731640.

The previous prime is 1122001987. The next prime is 1122002009. The reversal of 1122001991 is 1991002211.

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

It is not a de Polignac number, because 1122001991 - 2² = 1122001987 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1122001991.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1122001931) 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, 210761 + ... + 216018.

It is an arithmetic number, because the mean of its divisors is an integer number (153640800).

Almost surely, 2^1122001991 is an apocalyptic number.

1122001991 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

1122001991 is a deficient number, since it is larger than the sum of its proper divisors (107124409).

1122001991 is a wasteful number, since it uses less digits than its factorization.

1122001991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 427029.

The product of its (nonzero) digits is 324, while the sum is 26.

The square root of 1122001991 is about 33496.2981686036. The cubic root of 1122001991 is about 1039.1172214862.

The spelling of 1122001991 in words is "one billion, one hundred twenty-two million, one thousand, nine hundred ninety-one".