1210000221 has 16 divisors (see below), whose sum is σ = 1794597120. Its totient is φ = 805764960.

The previous prime is 1210000219. The next prime is 1210000249. The reversal of 1210000221 is 1220000121.

1210000221 is a nontrivial binomial coefficient, being equal to C(49194, 2).

It is not a de Polignac number, because 1210000221 - 2¹ = 1210000219 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1210000291) 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, 1 + ... + 49193.

It is an arithmetic number, because the mean of its divisors is an integer number (112162320).

Almost surely, 2^1210000221 is an apocalyptic number.

1210000221 is the 49193-rd triangular number and also the 24597-th hexagonal number.

It is an amenable number.

1210000221 is a deficient number, since it is larger than the sum of its proper divisors (584596899).

1210000221 is an equidigital number, since it uses as much as digits as its factorization.

1210000221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 50113 (or 50107 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 9.

The square root of 1210000221 is about 34785.0574385037. The cubic root of 1210000221 is about 1065.6023016421.

Adding to 1210000221 its reverse (1220000121), we get a palindrome (2430000342).

The spelling of 1210000221 in words is "one billion, two hundred ten million, two hundred twenty-one", and thus it is an aban number.