1221212099 has 12 divisors (see below), whose sum is σ = 1305214560. Its totient is φ = 1142266320.

The previous prime is 1221212089. The next prime is 1221212143. The reversal of 1221212099 is 9902121221.

It is a de Polignac number, because none of the positive numbers 2^k-1221212099 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1221212029) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 7109 + ... + 49929.

It is an arithmetic number, because the mean of its divisors is an integer number (108767880).

Almost surely, 2^1221212099 is an apocalyptic number.

1221212099 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

1221212099 is a deficient number, since it is larger than the sum of its proper divisors (84002461).

1221212099 is an equidigital number, since it uses as much as digits as its factorization.

1221212099 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42938 (or 42919 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 29.

The square root of 1221212099 is about 34945.8452323019. The cubic root of 1221212099 is about 1068.8834829163.

The spelling of 1221212099 in words is "one billion, two hundred twenty-one million, two hundred twelve thousand, ninety-nine".