1326521220 has 48 divisors (see below), whose sum is σ = 3932748288. Its totient is φ = 332930560.

The previous prime is 1326521213. The next prime is 1326521239. The reversal of 1326521220 is 221256231.

It is a super-2 number, since 2×1326521220² = 3519317094220576800, which contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 649236 + ... + 651275.

It is an arithmetic number, because the mean of its divisors is an integer number (81932256).

Almost surely, 2^1326521220 is an apocalyptic number.

1326521220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1326521220 is an abundant number, since it is smaller than the sum of its proper divisors (2606227068).

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

1326521220 is a wasteful number, since it uses less digits than its factorization.

1326521220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1300540 (or 1300538 counting only the distinct ones).

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

The square root of 1326521220 is about 36421.4390160521. The cubic root of 1326521220 is about 1098.7647897875.

Adding to 1326521220 its reverse (221256231), we get a palindrome (1547777451).

The spelling of 1326521220 in words is "one billion, three hundred twenty-six million, five hundred twenty-one thousand, two hundred twenty".