1216219101 has 4 divisors (see below), whose sum is σ = 1621625472. Its totient is φ = 810812732.

The previous prime is 1216219099. The next prime is 1216219111. The reversal of 1216219101 is 1019126121.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1216219101 - 2¹ = 1216219099 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1216219111) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 202703181 + ... + 202703186.

It is an arithmetic number, because the mean of its divisors is an integer number (405406368).

Almost surely, 2^1216219101 is an apocalyptic number.

It is an amenable number.

1216219101 is a deficient number, since it is larger than the sum of its proper divisors (405406371).

1216219101 is an equidigital number, since it uses as much as digits as its factorization.

1216219101 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 405406370.

The product of its (nonzero) digits is 216, while the sum is 24.

The square root of 1216219101 is about 34874.3329828686. The cubic root of 1216219101 is about 1067.4247619404.

The spelling of 1216219101 in words is "one billion, two hundred sixteen million, two hundred nineteen thousand, one hundred one".