1021000000 has 98 divisors (see below), whose sum is σ = 2535006614. Its totient is φ = 408000000.

The previous prime is 1020999989. The next prime is 1021000007. The reversal of 1021000000 is 1201.

1021000000 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 7 ways, for example, as 1020930304 + 69696 = 31952^2 + 264^2 .

It is a Harshad number since it is a multiple of its sum of digits (4).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1021000007) by changing a digit.

It is a polite number, since it can be written in 13 ways as a sum of consecutive naturals, for example, 999490 + ... + 1000510.

Almost surely, 2^1021000000 is an apocalyptic number.

1021000000 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 1021000000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1267503307).

1021000000 is an abundant number, since it is smaller than the sum of its proper divisors (1514006614).

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

1021000000 is an frugal number, since it uses more digits than its factorization.

1021000000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1063 (or 1028 counting only the distinct ones).

The product of its (nonzero) digits is 2, while the sum is 4.

The square root of 1021000000 is about 31953.0906173409. The cubic root of 1021000000 is about 1006.9515637846.

Adding to 1021000000 its reverse (1201), we get a palindrome (1021001201).

The spelling of 1021000000 in words is "one billion, twenty-one million", and thus it is an aban number and an uban number.