1020002000 has 80 divisors (see below), whose sum is σ = 2478508032. Its totient is φ = 405993600.

The previous prime is 1020001991. The next prime is 1020002017. The reversal of 1020002000 is 2000201.

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 (5).

It is a congruent number.

It is an unprimeable number.

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, 444857 + ... + 447143.

Almost surely, 2^1020002000 is an apocalyptic number.

1020002000 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 1020002000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1239254016).

1020002000 is an abundant number, since it is smaller than the sum of its proper divisors (1458506032).

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

1020002000 is a wasteful number, since it uses less digits than its factorization.

1020002000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2533 (or 2517 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 5.

The square root of 1020002000 is about 31937.4701565418. The cubic root of 1020002000 is about 1006.6233674830.

Adding to 1020002000 its reverse (2000201), we get a palindrome (1022002201).

The spelling of 1020002000 in words is "one billion, twenty million, two thousand".