1000990100 has 72 divisors (see below), whose sum is σ = 2451405600. Its totient is φ = 351433600.

The previous prime is 1000990079. The next prime is 1000990103. The reversal of 1000990100 is 10990001.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1000990103) by changing a digit.

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 23 ways as a sum of consecutive naturals, for example, 16211 + ... + 47589.

It is an arithmetic number, because the mean of its divisors is an integer number (34047300).

Almost surely, 2^1000990100 is an apocalyptic number.

1000990100 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 1000990100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1225702800).

1000990100 is an abundant number, since it is smaller than the sum of its proper divisors (1450415500).

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

1000990100 is a wasteful number, since it uses less digits than its factorization.

1000990100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31433 (or 31426 counting only the distinct ones).

The product of its (nonzero) digits is 81, while the sum is 20.

The square root of 1000990100 is about 31638.4275841895. The cubic root of 1000990100 is about 1000.3299244712.

Subtracting from 1000990100 its reverse (10990001), we obtain a palindrome (990000099).

The spelling of 1000990100 in words is "one billion, nine hundred ninety thousand, one hundred".