1216196550 has 72 divisors (see below), whose sum is σ = 3299989680. Its totient is φ = 321096000.

The previous prime is 1216196537. The next prime is 1216196551. The reversal of 1216196550 is 556916121.

1216196550 is a `hidden beast` number, since 1 + 2 + 16 + 1 + 96 + 550 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1216196551) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 32071 + ... + 58829.

It is an arithmetic number, because the mean of its divisors is an integer number (45833190).

Almost surely, 2^1216196550 is an apocalyptic number.

1216196550 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 1216196550, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1649994840).

1216196550 is an abundant number, since it is smaller than the sum of its proper divisors (2083793130).

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

1216196550 is a wasteful number, since it uses less digits than its factorization.

1216196550 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26878 (or 26870 counting only the distinct ones).

The product of its (nonzero) digits is 16200, while the sum is 36.

The square root of 1216196550 is about 34874.0096633582. The cubic root of 1216196550 is about 1067.4181645423.

The spelling of 1216196550 in words is "one billion, two hundred sixteen million, one hundred ninety-six thousand, five hundred fifty".