1021020 has 192 divisors, whose sum is σ = 4064256. Its totient is φ = 184320.

The previous prime is 1021019. The next prime is 1021043. The reversal of 1021020 is 201201.

1021020 = T₁₃ + T₁₄ + ... + T₁₈₂.

1021020 = 95² + 96² + ... + 157².

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (6).

It is a super Niven number, because it is divisible the sum of any subset of its (nonzero) digits.

It is a Saint-Exupery number, since it is equal to the product of the sides of a Pythagorean triangle: 221 × 21 × 220.

It is a congruent number.

It is an unprimeable number.

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 63 ways as a sum of consecutive naturals, for example, 60052 + ... + 60068.

It is an arithmetic number, because the mean of its divisors is an integer number (21168).

2^1021020 is an apocalyptic number.

1021020 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 1021020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2032128).

1021020 is an abundant number, since it is smaller than the sum of its proper divisors (3043236).

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

1021020 is a wasteful number, since it uses less digits than its factorization.

1021020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 60 (or 58 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 6.

The square root of 1021020 is about 1010.4553429024. The cubic root of 1021020 is about 100.6958138678.

Adding to 1021020 its reverse (201201), we get a palindrome (1222221).

The spelling of 1021020 in words is "one million, twenty-one thousand, twenty".