1216261219 has 2 divisors, whose sum is σ = 1216261220. Its totient is φ = 1216261218.

The previous prime is 1216261217. The next prime is 1216261271. The reversal of 1216261219 is 9121626121.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1216261219 - 2¹ = 1216261217 is a prime.

It is a super-2 number, since 2×1216261219² = 2958582705686731922, which contains 22 as substring.

Together with 1216261217, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (1216261217) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 608130609 + 608130610.

It is an arithmetic number, because the mean of its divisors is an integer number (608130610).

Almost surely, 2^1216261219 is an apocalyptic number.

1216261219 is a deficient number, since it is larger than the sum of its proper divisors (1).

1216261219 is an equidigital number, since it uses as much as digits as its factorization.

1216261219 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2592, while the sum is 31.

The square root of 1216261219 is about 34874.9368314840. The cubic root of 1216261219 is about 1067.4370835353.

The spelling of 1216261219 in words is "one billion, two hundred sixteen million, two hundred sixty-one thousand, two hundred nineteen".