1021240 has 48 divisors (see below), whose sum is σ = 2537640. Its totient is φ = 369600.

The previous prime is 1021217. The next prime is 1021243. The reversal of 1021240 is 421201.

It is a super-2 number, since 2×1021240² = 2085862275200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (10).

It is a plaindrome in base 13.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1021243) 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 11 ways as a sum of consecutive naturals, for example, 4735 + ... + 4945.

2^1021240 is an apocalyptic number.

1021240 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 1021240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1268820).

1021240 is an abundant number, since it is smaller than the sum of its proper divisors (1516400).

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

1021240 is a wasteful number, since it uses less digits than its factorization.

1021240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 244 (or 229 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 10.

The square root of 1021240 is about 1010.5641988513. The cubic root of 1021240 is about 100.7030456844.

Adding to 1021240 its reverse (421201), we get a palindrome (1442441).

The spelling of 1021240 in words is "one million, twenty-one thousand, two hundred forty".