1326121220 has 48 divisors (see below), whose sum is σ = 2859712128. Its totient is φ = 516253440.

The previous prime is 1326121187. The next prime is 1326121231. The reversal of 1326121220 is 221216231.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a junction number, because it is equal to n+sod(n) for n = 1326121192 and 1326121201.

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, 381209 + ... + 384671.

It is an arithmetic number, because the mean of its divisors is an integer number (59577336).

Almost surely, 2^1326121220 is an apocalyptic number.

1326121220 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 1326121220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1429856064).

1326121220 is an abundant number, since it is smaller than the sum of its proper divisors (1533590908).

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

1326121220 is a wasteful number, since it uses less digits than its factorization.

1326121220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3980 (or 3978 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 20.

The square root of 1326121220 is about 36415.9473308055. The cubic root of 1326121220 is about 1098.6543379548.

Adding to 1326121220 its reverse (221216231), we get a palindrome (1547337451).

The spelling of 1326121220 in words is "one billion, three hundred twenty-six million, one hundred twenty-one thousand, two hundred twenty".