1221011099 has 32 divisors (see below), whose sum is σ = 1579530240. Its totient is φ = 915868800.

The previous prime is 1221011093. The next prime is 1221011107. The reversal of 1221011099 is 9901101221.

It is a de Polignac number, because none of the positive numbers 2^k-1221011099 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1221011093) 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, 1033289 + ... + 1034469.

It is an arithmetic number, because the mean of its divisors is an integer number (49360320).

Almost surely, 2^1221011099 is an apocalyptic number.

1221011099 is a deficient number, since it is larger than the sum of its proper divisors (358519141).

1221011099 is a wasteful number, since it uses less digits than its factorization.

1221011099 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1691.

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

The square root of 1221011099 is about 34942.9692355987. The cubic root of 1221011099 is about 1068.8248369834.

The spelling of 1221011099 in words is "one billion, two hundred twenty-one million, eleven thousand, ninety-nine".