1021380 has 48 divisors (see below), whose sum is σ = 2963520. Its totient is φ = 262528.

The previous prime is 1021373. The next prime is 1021381. The reversal of 1021380 is 831201.

1021380 = T₃ + T₄ + ... + T₁₈₂.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is not an unprimeable number, because it can be changed into a prime (1021381) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1447 + ... + 2033.

It is an arithmetic number, because the mean of its divisors is an integer number (61740).

2^1021380 is an apocalyptic number.

1021380 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 1021380, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1481760).

1021380 is an abundant number, since it is smaller than the sum of its proper divisors (1942140).

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

1021380 is a wasteful number, since it uses less digits than its factorization.

1021380 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 628 (or 626 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 15.

The square root of 1021380 is about 1010.6334647141. The cubic root of 1021380 is about 100.7076472088.

Adding to 1021380 its reverse (831201), we get a palindrome (1852581).

The spelling of 1021380 in words is "one million, twenty-one thousand, three hundred eighty".