1021000008 has 128 divisors (see below), whose sum is σ = 3101932800. Its totient is φ = 274332672.

The previous prime is 1021000007. The next prime is 1021000009. The reversal of 1021000008 is 8000001201.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (1021000007) and next prime (1021000009).

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a junction number, because it is equal to n+sod(n) for n = 1020999957 and 1021000002.

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 31 ways as a sum of consecutive naturals, for example, 824766 + ... + 826002.

It is an arithmetic number, because the mean of its divisors is an integer number (24233850).

Almost surely, 2^1021000008 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1021000008, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1550966400).

1021000008 is an abundant number, since it is smaller than the sum of its proper divisors (2080932792).

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

1021000008 is a wasteful number, since it uses less digits than its factorization.

1021000008 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1304 (or 1266 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 12.

The square root of 1021000008 is about 31953.0907425244. The cubic root of 1021000008 is about 1006.9515664146.

Adding to 1021000008 its reverse (8000001201), we get a palindrome (9021001209).

The spelling of 1021000008 in words is "one billion, twenty-one million, eight", and thus it is an aban number and an uban number.