1216154880 has 216 divisors, whose sum is σ = 4235311080. Its totient is φ = 322191360.

The previous prime is 1216154867. The next prime is 1216154903. The reversal of 1216154880 is 884516121.

1216154880 is a `hidden beast` number, since 12 + 161 + 5 + 488 + 0 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 269485056 + 946669824 = 16416^2 + 30768^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2637850 + ... + 2638310.

Almost surely, 2^1216154880 is an apocalyptic number.

1216154880 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 1216154880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2117655540).

1216154880 is an abundant number, since it is smaller than the sum of its proper divisors (3019156200).

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

1216154880 is a wasteful number, since it uses less digits than its factorization.

1216154880 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 717 (or 700 counting only the distinct ones).

The product of its (nonzero) digits is 15360, while the sum is 36.

The square root of 1216154880 is about 34873.4122219206. The cubic root of 1216154880 is about 1067.4059735789.

The spelling of 1216154880 in words is "one billion, two hundred sixteen million, one hundred fifty-four thousand, eight hundred eighty".