1216687500 has 336 divisors, whose sum is σ = 4549941760. Its totient is φ = 275400000.

The previous prime is 1216687499. The next prime is 1216687573. The reversal of 1216687500 is 57866121.

1216687500 is a `hidden beast` number, since 12 + 1 + 66 + 87 + 500 = 666.

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

It is an unprimeable number.

It is a polite number, since it can be written in 111 ways as a sum of consecutive naturals, for example, 11812449 + ... + 11812551.

Almost surely, 2^1216687500 is an apocalyptic number.

1216687500 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 1216687500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2274970880).

1216687500 is an abundant number, since it is smaller than the sum of its proper divisors (3333254260).

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

1216687500 is an equidigital number, since it uses as much as digits as its factorization.

1216687500 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 153 (or 120 counting only the distinct ones).

The product of its (nonzero) digits is 20160, while the sum is 36.

The square root of 1216687500 is about 34881.0478627005. The cubic root of 1216687500 is about 1067.5617757726.

The spelling of 1216687500 in words is "one billion, two hundred sixteen million, six hundred eighty-seven thousand, five hundred".