1216305530 has 32 divisors (see below), whose sum is σ = 2470746240. Its totient is φ = 427040320.

The previous prime is 1216305523. The next prime is 1216305569. The reversal of 1216305530 is 355036121.

It is a self number, because there is not a number n which added to its sum of digits gives 1216305530.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 187454 + ... + 193833.

It is an arithmetic number, because the mean of its divisors is an integer number (77210820).

Almost surely, 2^1216305530 is an apocalyptic number.

1216305530 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1216305530 is an abundant number, since it is smaller than the sum of its proper divisors (1254440710).

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

1216305530 is a wasteful number, since it uses less digits than its factorization.

1216305530 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 381334.

The product of its (nonzero) digits is 2700, while the sum is 26.

The square root of 1216305530 is about 34875.5721100027. The cubic root of 1216305530 is about 1067.4500463839.

The spelling of 1216305530 in words is "one billion, two hundred sixteen million, three hundred five thousand, five hundred thirty".