1216399927 has 4 divisors (see below), whose sum is σ = 1216488736. Its totient is φ = 1216311120.

The previous prime is 1216399909. The next prime is 1216399999. The reversal of 1216399927 is 7299936121.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 1216399927 - 2²³ = 1208011319 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 (1216399907) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 19023 + ... + 52864.

It is an arithmetic number, because the mean of its divisors is an integer number (304122184).

Almost surely, 2^1216399927 is an apocalyptic number.

1216399927 is a deficient number, since it is larger than the sum of its proper divisors (88809).

1216399927 is an equidigital number, since it uses as much as digits as its factorization.

1216399927 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 88808.

The product of its digits is 367416, while the sum is 49.

The square root of 1216399927 is about 34876.9254235519. The cubic root of 1216399927 is about 1067.4776604641.

The spelling of 1216399927 in words is "one billion, two hundred sixteen million, three hundred ninety-nine thousand, nine hundred twenty-seven".