1216091140 has 36 divisors (see below), whose sum is σ = 2807065548. Its totient is φ = 442214080.

The previous prime is 1216091137. The next prime is 1216091147. The reversal of 1216091140 is 411906121.

It can be written as a sum of positive squares in 2 ways, for example, as 208282624 + 1007808516 = 14432^2 + 31746^2 .

It is not an unprimeable number, because it can be changed into a prime (1216091147) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 248839 + ... + 253678.

It is an arithmetic number, because the mean of its divisors is an integer number (77974043).

Almost surely, 2^1216091140 is an apocalyptic number.

1216091140 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1216091140 is an abundant number, since it is smaller than the sum of its proper divisors (1590974408).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1216091140 is a wasteful number, since it uses less digits than its factorization.

1216091140 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 502548 (or 502535 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 25.

The square root of 1216091140 is about 34872.4983332138. The cubic root of 1216091140 is about 1067.3873252838.

Adding to 1216091140 its reverse (411906121), we get a palindrome (1627997261).

The spelling of 1216091140 in words is "one billion, two hundred sixteen million, ninety-one thousand, one hundred forty".