1220521530 has 16 divisors (see below), whose sum is σ = 2929251744. Its totient is φ = 325472400.

The previous prime is 1220521517. The next prime is 1220521531. The reversal of 1220521530 is 351250221.

It is a junction number, because it is equal to n+sod(n) for n = 1220521497 and 1220521506.

It is not an unprimeable number, because it can be changed into a prime (1220521531) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 20341996 + ... + 20342055.

It is an arithmetic number, because the mean of its divisors is an integer number (183078234).

Almost surely, 2^1220521530 is an apocalyptic number.

1220521530 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1220521530 is an abundant number, since it is smaller than the sum of its proper divisors (1708730214).

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

1220521530 is a wasteful number, since it uses less digits than its factorization.

1220521530 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40684061.

The product of its (nonzero) digits is 600, while the sum is 21.

The square root of 1220521530 is about 34935.9632756848. The cubic root of 1220521530 is about 1068.6819681054.

Adding to 1220521530 its reverse (351250221), we get a palindrome (1571771751).

The spelling of 1220521530 in words is "one billion, two hundred twenty million, five hundred twenty-one thousand, five hundred thirty".