1521920 has 72 divisors (see below), whose sum is σ = 3863160. Its totient is φ = 573440.

The previous prime is 1521913. The next prime is 1521937. The reversal of 1521920 is 291251.

It can be written as a sum of positive squares in 4 ways, for example, as 4096 + 1517824 = 64^2 + 1232^2 .

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 = 1521892 and 1521901.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 37100 + ... + 37140.

It is an arithmetic number, because the mean of its divisors is an integer number (53655).

2^1521920 is an apocalyptic number.

1521920 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 1521920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1931580).

1521920 is an abundant number, since it is smaller than the sum of its proper divisors (2341240).

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

1521920 is an equidigital number, since it uses as much as digits as its factorization.

1521920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 91 (or 77 counting only the distinct ones).

The product of its (nonzero) digits is 180, while the sum is 20.

The square root of 1521920 is about 1233.6612176769. The cubic root of 1521920 is about 115.0263329742.

The spelling of 1521920 in words is "one million, five hundred twenty-one thousand, nine hundred twenty".