1321233320 has 64 divisors (see below), whose sum is σ = 3288781440. Its totient is φ = 473670400.

The previous prime is 1321233317. The next prime is 1321233337. The reversal of 1321233320 is 233321231.

1321233320 = T₄₃₉ + T₄₄₀ + ... + T₂₀₀₀.

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 = 1321233292 and 1321233301.

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, 10094 + ... + 52386.

It is an arithmetic number, because the mean of its divisors is an integer number (51387210).

Almost surely, 2^1321233320 is an apocalyptic number.

1321233320 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 1321233320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1644390720).

1321233320 is an abundant number, since it is smaller than the sum of its proper divisors (1967548120).

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

1321233320 is a wasteful number, since it uses less digits than its factorization.

1321233320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42386 (or 42382 counting only the distinct ones).

The product of its (nonzero) digits is 648, while the sum is 20.

The square root of 1321233320 is about 36348.7732942943. The cubic root of 1321233320 is about 1097.3028466450.

Adding to 1321233320 its reverse (233321231), we get a palindrome (1554554551).

The spelling of 1321233320 in words is "one billion, three hundred twenty-one million, two hundred thirty-three thousand, three hundred twenty".