1921320 has 80 divisors (see below), whose sum is σ = 6468660. Its totient is φ = 511488.

The previous prime is 1921319. The next prime is 1921327. The reversal of 1921320 is 231291.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 1920996 + 324 = 1386^2 + 18^2 .

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 1921293 and 1921302.

It is not an unprimeable number, because it can be changed into a prime (1921327) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 2944 + ... + 3536.

2^1921320 is an apocalyptic number.

1921320 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 1921320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3234330).

1921320 is an abundant number, since it is smaller than the sum of its proper divisors (4547340).

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

1921320 is a wasteful number, since it uses less digits than its factorization.

1921320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 616 (or 603 counting only the distinct ones).

The product of its (nonzero) digits is 108, while the sum is 18.

The square root of 1921320 is about 1386.1168781888. The cubic root of 1921320 is about 124.3177766779.

The spelling of 1921320 in words is "one million, nine hundred twenty-one thousand, three hundred twenty".