1021002000 has 80 divisors (see below), whose sum is σ = 3291729792. Its totient is φ = 272265600.

The previous prime is 1021001999. The next prime is 1021002001. The reversal of 1021002000 is 2001201.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (1021001999) and next prime (1021002001).

It is a tau number, because it is divible by the number of its divisors (80).

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 self number, because there is not a number n which added to its sum of digits gives 1021002000.

It is not an unprimeable number, because it can be changed into a prime (1021002001) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 79084 + ... + 91083.

Almost surely, 2^1021002000 is an apocalyptic number.

1021002000 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1021002000 is an abundant number, since it is smaller than the sum of its proper divisors (2270727792).

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

1021002000 is a wasteful number, since it uses less digits than its factorization.

1021002000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 170193 (or 170177 counting only the distinct ones).

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

The square root of 1021002000 is about 31953.1219132028. The cubic root of 1021002000 is about 1006.9522212779.

Adding to 1021002000 its reverse (2001201), we get a palindrome (1023003201).

The spelling of 1021002000 in words is "one billion, twenty-one million, two thousand".