1216881255 has 16 divisors (see below), whose sum is σ = 1948032000. Its totient is φ = 648662688.

The previous prime is 1216881251. The next prime is 1216881329. The reversal of 1216881255 is 5521886121.

It is not a de Polignac number, because 1216881255 - 2² = 1216881251 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1216881251) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9694 + ... + 50276.

It is an arithmetic number, because the mean of its divisors is an integer number (121752000).

Almost surely, 2^1216881255 is an apocalyptic number.

1216881255 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

1216881255 is a deficient number, since it is larger than the sum of its proper divisors (731150745).

1216881255 is a wasteful number, since it uses less digits than its factorization.

1216881255 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42590.

The product of its digits is 38400, while the sum is 39.

The square root of 1216881255 is about 34883.8251199607. The cubic root of 1216881255 is about 1067.6184417757.

The spelling of 1216881255 in words is "one billion, two hundred sixteen million, eight hundred eighty-one thousand, two hundred fifty-five".