1100991221 has 16 divisors (see below), whose sum is σ = 1239235008. Its totient is φ = 977573520.

The previous prime is 1100991173. The next prime is 1100991259. The reversal of 1100991221 is 1221990011.

It is a de Polignac number, because none of the positive numbers 2^k-1100991221 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1100961221) 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, 47615 + ... + 66851.

It is an arithmetic number, because the mean of its divisors is an integer number (77452188).

Almost surely, 2^1100991221 is an apocalyptic number.

1100991221 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1100991221 is a deficient number, since it is larger than the sum of its proper divisors (138243787).

1100991221 is an equidigital number, since it uses as much as digits as its factorization.

1100991221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19313 (or 19291 counting only the distinct ones).

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

The square root of 1100991221 is about 33181.1877575231. The cubic root of 1100991221 is about 1032.5900883467.

The spelling of 1100991221 in words is "one billion, one hundred million, nine hundred ninety-one thousand, two hundred twenty-one".