1216155941 has 60 divisors (see below), whose sum is σ = 1693091520. Its totient is φ = 863684640.

The previous prime is 1216155931. The next prime is 1216155949. The reversal of 1216155941 is 1495516121.

It is not a de Polignac number, because 1216155941 - 2¹⁸ = 1215893797 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 (1216155949) 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 59 ways as a sum of consecutive naturals, for example, 15394340 + ... + 15394418.

It is an arithmetic number, because the mean of its divisors is an integer number (28218192).

Almost surely, 2^1216155941 is an apocalyptic number.

1216155941 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1216155941 is a deficient number, since it is larger than the sum of its proper divisors (476935579).

1216155941 is an frugal number, since it uses more digits than its factorization.

1216155941 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 156 (or 110 counting only the distinct ones).

The product of its digits is 10800, while the sum is 35.

The square root of 1216155941 is about 34873.4274340794. The cubic root of 1216155941 is about 1067.4062839882.

The spelling of 1216155941 in words is "one billion, two hundred sixteen million, one hundred fifty-five thousand, nine hundred forty-one".