2101001004 has 120 divisors (see below), whose sum is σ = 5594997408. Its totient is φ = 687398400.

The previous prime is 2101000999. The next prime is 2101001009. The reversal of 2101001004 is 4001001012.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (2101000999) and next prime (2101001009).

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

It is not an unprimeable number, because it can be changed into a prime (2101001009) by changing a digit.

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 39 ways as a sum of consecutive naturals, for example, 5239204 + ... + 5239604.

Almost surely, 2^2101001004 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 2101001004, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2797498704).

2101001004 is an abundant number, since it is smaller than the sum of its proper divisors (3493996404).

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

2101001004 is a wasteful number, since it uses less digits than its factorization.

2101001004 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 677 (or 666 counting only the distinct ones).

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

The square root of 2101001004 is about 45836.6774973928. The cubic root of 2101001004 is about 1280.7826032804.

Adding to 2101001004 its reverse (4001001012), we get a palindrome (6102002016).

The spelling of 2101001004 in words is "two billion, one hundred one million, one thousand, four".