1021001020 has 48 divisors (see below), whose sum is σ = 2322482400. Its totient is φ = 374789376.

The previous prime is 1021000963. The next prime is 1021001029. The reversal of 1021001020 is 201001201.

It is a junction number, because it is equal to n+sod(n) for n = 1021000994 and 1021001012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1021001029) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 33631 + ... + 56329.

It is an arithmetic number, because the mean of its divisors is an integer number (48385050).

Almost surely, 2^1021001020 is an apocalyptic number.

1021001020 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 1021001020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1161241200).

1021001020 is an abundant number, since it is smaller than the sum of its proper divisors (1301481380).

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

1021001020 is a wasteful number, since it uses less digits than its factorization.

1021001020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22894 (or 22892 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 7.

The square root of 1021001020 is about 31953.1065782343. The cubic root of 1021001020 is about 1006.9518991063.

Adding to 1021001020 its reverse (201001201), we get a palindrome (1222002221).

The spelling of 1021001020 in words is "one billion, twenty-one million, one thousand, twenty".