1221210109 has 8 divisors (see below), whose sum is σ = 1405036800. Its totient is φ = 1039725456.

The previous prime is 1221210043. The next prime is 1221210119. The reversal of 1221210109 is 9010121221.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1221210109 - 2¹¹ = 1221208061 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 (1221210119) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 584389 + ... + 586474.

It is an arithmetic number, because the mean of its divisors is an integer number (175629600).

Almost surely, 2^1221210109 is an apocalyptic number.

It is an amenable number.

1221210109 is a deficient number, since it is larger than the sum of its proper divisors (183826691).

1221210109 is a wasteful number, since it uses less digits than its factorization.

1221210109 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1171019.

The product of its (nonzero) digits is 72, while the sum is 19.

The square root of 1221210109 is about 34945.8167596638. The cubic root of 1221210109 is about 1068.8829023239.

The spelling of 1221210109 in words is "one billion, two hundred twenty-one million, two hundred ten thousand, one hundred nine".