21403010400 has 144 divisors (see below), whose sum is σ = 71149446144. Its totient is φ = 5586004480.

The previous prime is 21403010393. The next prime is 21403010443. The reversal of 21403010400 is 401030412.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 21403010400.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 17929 + ... + 207671.

It is an arithmetic number, because the mean of its divisors is an integer number (494093376).

Almost surely, 2^21403010400 is an apocalyptic number.

21403010400 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 21403010400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35574723072).

21403010400 is an abundant number, since it is smaller than the sum of its proper divisors (49746435744).

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

21403010400 is a wasteful number, since it uses less digits than its factorization.

21403010400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 189813 (or 189800 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 15.

Adding to 21403010400 its reverse (401030412), we get a palindrome (21804040812).

The spelling of 21403010400 in words is "twenty-one billion, four hundred three million, ten thousand, four hundred".