1216500500 has 24 divisors (see below), whose sum is σ = 2656838184. Its totient is φ = 486600000.

The previous prime is 1216500469. The next prime is 1216500533. The reversal of 1216500500 is 50056121.

It can be written as a sum of positive squares in 4 ways, for example, as 38912644 + 1177587856 = 6238^2 + 34316^2 .

It is a hoax number, since the sum of its digits (20) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1216001 + ... + 1217000.

It is an arithmetic number, because the mean of its divisors is an integer number (110701591).

Almost surely, 2^1216500500 is an apocalyptic number.

1216500500 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1216500500 is an abundant number, since it is smaller than the sum of its proper divisors (1440337684).

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

1216500500 is a wasteful number, since it uses less digits than its factorization.

1216500500 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2433020 (or 2433008 counting only the distinct ones).

The product of its (nonzero) digits is 300, while the sum is 20.

The square root of 1216500500 is about 34878.3672209580. The cubic root of 1216500500 is about 1067.5070796460.

Adding to 1216500500 its reverse (50056121), we get a palindrome (1266556621).

The spelling of 1216500500 in words is "one billion, two hundred sixteen million, five hundred thousand, five hundred".