21130030400 has 42 divisors (see below), whose sum is σ = 51993084990. Its totient is φ = 8452011520.

The previous prime is 21130030367. The next prime is 21130030403. The reversal of 21130030400 is 403003112.

It can be written as a sum of positive squares in 3 ways, for example, as 2636206336 + 18493824064 = 51344^2 + 135992^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21130030403) 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 5 ways as a sum of consecutive naturals, for example, 6601535 + ... + 6604734.

It is an arithmetic number, because the mean of its divisors is an integer number (1237930595).

Almost surely, 2^21130030400 is an apocalyptic number.

21130030400 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21130030400 is an abundant number, since it is smaller than the sum of its proper divisors (30863054590).

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

21130030400 is a wasteful number, since it uses less digits than its factorization.

21130030400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13206291 (or 13206276 counting only the distinct ones).

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

Adding to 21130030400 its reverse (403003112), we get a palindrome (21533033512).

The spelling of 21130030400 in words is "twenty-one billion, one hundred thirty million, thirty thousand, four hundred".