1216621332 has 36 divisors (see below), whose sum is σ = 3125769556. Its totient is φ = 398891520.

The previous prime is 1216621321. The next prime is 1216621339. The reversal of 1216621332 is 2331266121.

1216621332 is a `hidden beast` number, since 1 + 2 + 1 + 6 + 621 + 3 + 32 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 536663556 + 679957776 = 23166^2 + 26076^2 .

It is a tau number, because it is divible by the number of its divisors (36).

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

It is a junction number, because it is equal to n+sod(n) for n = 1216621296 and 1216621305.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1216621339) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 274813 + ... + 279204.

Almost surely, 2^1216621332 is an apocalyptic number.

1216621332 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

1216621332 is an abundant number, since it is smaller than the sum of its proper divisors (1909148224).

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

1216621332 is a wasteful number, since it uses less digits than its factorization.

1216621332 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 554088 (or 554083 counting only the distinct ones).

The product of its digits is 2592, while the sum is 27.

The square root of 1216621332 is about 34880.0993691245. The cubic root of 1216621332 is about 1067.5424227593.

Adding to 1216621332 its reverse (2331266121), we get a palindrome (3547887453).

The spelling of 1216621332 in words is "one billion, two hundred sixteen million, six hundred twenty-one thousand, three hundred thirty-two".