1221000211 has 16 divisors (see below), whose sum is σ = 1303241760. Its totient is φ = 1140652800.

The previous prime is 1221000203. The next prime is 1221000227. The reversal of 1221000211 is 1120001221.

It is a cyclic number.

It is not a de Polignac number, because 1221000211 - 2³ = 1221000203 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1221000251) 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, 530415 + ... + 532711.

It is an arithmetic number, because the mean of its divisors is an integer number (81452610).

Almost surely, 2^1221000211 is an apocalyptic number.

1221000211 is a deficient number, since it is larger than the sum of its proper divisors (82241549).

1221000211 is a wasteful number, since it uses less digits than its factorization.

1221000211 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2694.

The product of its (nonzero) digits is 8, while the sum is 10.

The square root of 1221000211 is about 34942.8134385312. The cubic root of 1221000211 is about 1068.8216599991.

Adding to 1221000211 its reverse (1120001221), we get a palindrome (2341001432).

The spelling of 1221000211 in words is "one billion, two hundred twenty-one million, two hundred eleven", and thus it is an aban number.