1216045320 has 128 divisors (see below), whose sum is σ = 4202496000. Its totient is φ = 275740416.

The previous prime is 1216045307. The next prime is 1216045321. The reversal of 1216045320 is 235406121.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is not an unprimeable number, because it can be changed into a prime (1216045321) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 100981 + ... + 112379.

It is an arithmetic number, because the mean of its divisors is an integer number (32832000).

Almost surely, 2^1216045320 is an apocalyptic number.

1216045320 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 1216045320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2101248000).

1216045320 is an abundant number, since it is smaller than the sum of its proper divisors (2986450680).

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

1216045320 is a wasteful number, since it uses less digits than its factorization.

1216045320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11547 (or 11543 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 24.

The square root of 1216045320 is about 34871.8413623370. The cubic root of 1216045320 is about 1067.3739194077.

The spelling of 1216045320 in words is "one billion, two hundred sixteen million, forty-five thousand, three hundred twenty".