1216520180 has 48 divisors (see below), whose sum is σ = 2596361040. Its totient is φ = 478706688.

The previous prime is 1216520171. The next prime is 1216520213. The reversal of 1216520180 is 810256121.

It can be written as a sum of positive squares in 8 ways, for example, as 36048016 + 1180472164 = 6004^2 + 34358^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 742322 + ... + 743958.

It is an arithmetic number, because the mean of its divisors is an integer number (54090855).

Almost surely, 2^1216520180 is an apocalyptic number.

1216520180 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1216520180 is an abundant number, since it is smaller than the sum of its proper divisors (1379840860).

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

1216520180 is a wasteful number, since it uses less digits than its factorization.

1216520180 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2228 (or 2226 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 26.

The square root of 1216520180 is about 34878.6493431153. The cubic root of 1216520180 is about 1067.5128361653.

The spelling of 1216520180 in words is "one billion, two hundred sixteen million, five hundred twenty thousand, one hundred eighty".