1216331749 has 2 divisors, whose sum is σ = 1216331750. Its totient is φ = 1216331748.

The previous prime is 1216331737. The next prime is 1216331771. The reversal of 1216331749 is 9471336121.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 773229249 + 443102500 = 27807^2 + 21050^2 .

It is a cyclic number.

It is not a de Polignac number, because 1216331749 - 2²⁷ = 1082114021 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1216331719) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 608165874 + 608165875.

It is an arithmetic number, because the mean of its divisors is an integer number (608165875).

Almost surely, 2^1216331749 is an apocalyptic number.

It is an amenable number.

1216331749 is a deficient number, since it is larger than the sum of its proper divisors (1).

1216331749 is an equidigital number, since it uses as much as digits as its factorization.

1216331749 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 27216, while the sum is 37.

The square root of 1216331749 is about 34875.9480014522. The cubic root of 1216331749 is about 1067.4577164062.

The spelling of 1216331749 in words is "one billion, two hundred sixteen million, three hundred thirty-one thousand, seven hundred forty-nine".