1216613616 has 40 divisors (see below), whose sum is σ = 3144359760. Its totient is φ = 405351936.

The previous prime is 1216613603. The next prime is 1216613617. The reversal of 1216613616 is 6163166121.

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1216613617) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 135276 + ... + 143988.

It is an arithmetic number, because the mean of its divisors is an integer number (78608994).

Almost surely, 2^1216613616 is an apocalyptic number.

1216613616 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

1216613616 is an abundant number, since it is smaller than the sum of its proper divisors (1927746144).

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

1216613616 is a wasteful number, since it uses less digits than its factorization.

1216613616 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11633 (or 11627 counting only the distinct ones).

The product of its digits is 7776, while the sum is 33.

The square root of 1216613616 is about 34879.9887614661. The cubic root of 1216613616 is about 1067.5401659150.

Adding to 1216613616 its reverse (6163166121), we get a palindrome (7379779737).

The spelling of 1216613616 in words is "one billion, two hundred sixteen million, six hundred thirteen thousand, six hundred sixteen".