1216787049 has 16 divisors (see below), whose sum is σ = 1806280000. Its totient is φ = 809556768.

The previous prime is 1216787027. The next prime is 1216787057. The reversal of 1216787049 is 9407876121.

It is a happy number.

It is not a de Polignac number, because 1216787049 - 2⁸ = 1216786793 is a prime.

It is a super-2 number, since 2×1216787049² = 2961141445228256802, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1216786995 and 1216787013.

It is not an unprimeable number, because it can be changed into a prime (1216787059) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 31684 + ... + 58629.

It is an arithmetic number, because the mean of its divisors is an integer number (112892500).

Almost surely, 2^1216787049 is an apocalyptic number.

It is an amenable number.

1216787049 is a deficient number, since it is larger than the sum of its proper divisors (589492951).

1216787049 is an equidigital number, since it uses as much as digits as its factorization.

1216787049 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 90821 (or 90815 counting only the distinct ones).

The product of its (nonzero) digits is 169344, while the sum is 45.

The square root of 1216787049 is about 34882.4748118593. The cubic root of 1216787049 is about 1067.5908908381.

The spelling of 1216787049 in words is "one billion, two hundred sixteen million, seven hundred eighty-seven thousand, forty-nine".