1216490220 has 144 divisors (see below), whose sum is σ = 4155540480. Its totient is φ = 285379200.

The previous prime is 1216490161. The next prime is 1216490221. The reversal of 1216490220 is 220946121.

1216490220 is a `hidden beast` number, since 12 + 1 + 649 + 0 + 2 + 2 + 0 = 666.

It is not an unprimeable number, because it can be changed into a prime (1216490221) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 51471 + ... + 71289.

It is an arithmetic number, because the mean of its divisors is an integer number (28857920).

Almost surely, 2^1216490220 is an apocalyptic number.

1216490220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1216490220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2077770240).

1216490220 is an abundant number, since it is smaller than the sum of its proper divisors (2939050260).

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

1216490220 is a wasteful number, since it uses less digits than its factorization.

1216490220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19876 (or 19871 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 27.

The square root of 1216490220 is about 34878.2198513628. The cubic root of 1216490220 is about 1067.5040726589.

The spelling of 1216490220 in words is "one billion, two hundred sixteen million, four hundred ninety thousand, two hundred twenty".