1001021004 has 144 divisors (see below), whose sum is σ = 2806876800. Its totient is φ = 311008896.

The previous prime is 1001020997. The next prime is 1001021057. The reversal of 1001021004 is 4001201001.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1236952 + ... + 1237760.

It is an arithmetic number, because the mean of its divisors is an integer number (19492200).

Almost surely, 2^1001021004 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 1001021004, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1403438400).

1001021004 is an abundant number, since it is smaller than the sum of its proper divisors (1805855796).

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

1001021004 is a wasteful number, since it uses less digits than its factorization.

1001021004 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 914 (or 900 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 9.

The square root of 1001021004 is about 31638.9159738446. The cubic root of 1001021004 is about 1000.3402189046.

Adding to 1001021004 its reverse (4001201001), we get a palindrome (5002222005).

The spelling of 1001021004 in words is "one billion, one million, twenty-one thousand, four".