21031003400 has 96 divisors (see below), whose sum is σ = 53536394880. Its totient is φ = 7619808000.

The previous prime is 21031003369. The next prime is 21031003403. The reversal of 21031003400 is 430013012.

It is not an unprimeable number, because it can be changed into a prime (21031003403) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 592145 + ... + 626655.

It is an arithmetic number, because the mean of its divisors is an integer number (557670780).

Almost surely, 2^21031003400 is an apocalyptic number.

21031003400 is a gapful number since it is divisible by the number (20) 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 21031003400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26768197440).

21031003400 is an abundant number, since it is smaller than the sum of its proper divisors (32505391480).

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

21031003400 is a wasteful number, since it uses less digits than its factorization.

21031003400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34815 (or 34806 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 14.

Adding to 21031003400 its reverse (430013012), we get a palindrome (21461016412).

The spelling of 21031003400 in words is "twenty-one billion, thirty-one million, three thousand, four hundred".