1216205000 has 80 divisors (see below), whose sum is σ = 2886576000. Its totient is φ = 480168000.

The previous prime is 1216204993. The next prime is 1216205009. The reversal of 1216205000 is 5026121.

It is a self number, because there is not a number n which added to its sum of digits gives 1216205000.

It is not an unprimeable number, because it can be changed into a prime (1216205009) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 393461 + ... + 396539.

It is an arithmetic number, because the mean of its divisors is an integer number (36082200).

Almost surely, 2^1216205000 is an apocalyptic number.

1216205000 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 1216205000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1443288000).

1216205000 is an abundant number, since it is smaller than the sum of its proper divisors (1670371000).

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

1216205000 is an equidigital number, since it uses as much as digits as its factorization.

1216205000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3184 (or 3165 counting only the distinct ones).

The product of its (nonzero) digits is 120, while the sum is 17.

The square root of 1216205000 is about 34874.1308135414. The cubic root of 1216205000 is about 1067.4206366380.

The spelling of 1216205000 in words is "one billion, two hundred sixteen million, two hundred five thousand".