1100019991 has 32 divisors (see below), whose sum is σ = 1352885760. Its totient is φ = 873524736.

The previous prime is 1100019961. The next prime is 1100020021. The reversal of 1100019991 is 1999100011.

It is an interprime number because it is at equal distance from previous prime (1100019961) and next prime (1100020021).

It is not a de Polignac number, because 1100019991 - 2⁷ = 1100019863 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1100019911) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1329720 + ... + 1330546.

It is an arithmetic number, because the mean of its divisors is an integer number (42277680).

Almost surely, 2^1100019991 is an apocalyptic number.

1100019991 is a deficient number, since it is larger than the sum of its proper divisors (252865769).

1100019991 is a wasteful number, since it uses less digits than its factorization.

1100019991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1063.

The product of its (nonzero) digits is 729, while the sum is 31.

The square root of 1100019991 is about 33166.5492778492. The cubic root of 1100019991 is about 1032.2863688463.

The spelling of 1100019991 in words is "one billion, one hundred million, nineteen thousand, nine hundred ninety-one".