1321393920 has 576 divisors, whose sum is σ = 5439329280. Its totient is φ = 265420800.

The previous prime is 1321393919. The next prime is 1321393981. The reversal of 1321393920 is 293931231.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 12122826 + ... + 12122934.

It is an arithmetic number, because the mean of its divisors is an integer number (9443280).

Almost surely, 2^1321393920 is an apocalyptic number.

1321393920 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 1321393920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2719664640).

1321393920 is an abundant number, since it is smaller than the sum of its proper divisors (4117935360).

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

1321393920 is a wasteful number, since it uses less digits than its factorization.

1321393920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 192 (or 178 counting only the distinct ones).

The product of its (nonzero) digits is 8748, while the sum is 33.

The square root of 1321393920 is about 36350.9823801228. The cubic root of 1321393920 is about 1097.3473050296.

The spelling of 1321393920 in words is "one billion, three hundred twenty-one million, three hundred ninety-three thousand, nine hundred twenty".