1021040020 has 96 divisors (see below), whose sum is σ = 2878960896. Its totient is φ = 293760000.

The previous prime is 1021039997. The next prime is 1021040029. The reversal of 1021040020 is 200401201.

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

It is a junction number, because it is equal to n+sod(n) for n = 1021039979 and 1021040006.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1021040029) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 5481 + ... + 45520.

It is an arithmetic number, because the mean of its divisors is an integer number (29989176).

Almost surely, 2^1021040020 is an apocalyptic number.

1021040020 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 1021040020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1439480448).

1021040020 is an abundant number, since it is smaller than the sum of its proper divisors (1857920876).

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

1021040020 is a wasteful number, since it uses less digits than its factorization.

1021040020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51041 (or 51039 counting only the distinct ones).

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

The square root of 1021040020 is about 31953.7168417072. The cubic root of 1021040020 is about 1006.9647200612.

Adding to 1021040020 its reverse (200401201), we get a palindrome (1221441221).

The spelling of 1021040020 in words is "one billion, twenty-one million, forty thousand, twenty".