1220505516 has 96 divisors (see below), whose sum is σ = 3210197760. Its totient is φ = 400982400.

The previous prime is 1220505509. The next prime is 1220505521. The reversal of 1220505516 is 6155050221.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a self number, because there is not a number n which added to its sum of digits gives 1220505516.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3975435 + ... + 3975741.

It is an arithmetic number, because the mean of its divisors is an integer number (33439560).

Almost surely, 2^1220505516 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1220505516, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1605098880).

1220505516 is an abundant number, since it is smaller than the sum of its proper divisors (1989692244).

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

1220505516 is a wasteful number, since it uses less digits than its factorization.

1220505516 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 732 (or 724 counting only the distinct ones).

The product of its (nonzero) digits is 3000, while the sum is 27.

The square root of 1220505516 is about 34935.7340841723. The cubic root of 1220505516 is about 1068.6772941614.

Adding to 1220505516 its reverse (6155050221), we get a palindrome (7375555737).

The spelling of 1220505516 in words is "one billion, two hundred twenty million, five hundred five thousand, five hundred sixteen".