21400104 has 64 divisors (see below), whose sum is σ = 59005440. Its totient is φ = 6413760.

The previous prime is 21400103. The next prime is 21400109. The reversal of 21400104 is 40100412.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a self number, because there is not a number n which added to its sum of digits gives 21400104.

It is not an unprimeable number, because it can be changed into a prime (21400103) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 26799 + ... + 27585.

It is an arithmetic number, because the mean of its divisors is an integer number (921960).

Almost surely, 2^21400104 is an apocalyptic number.

21400104 is a gapful number since it is divisible by the number (24) 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 21400104, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29502720).

21400104 is an abundant number, since it is smaller than the sum of its proper divisors (37605336).

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

21400104 is a wasteful number, since it uses less digits than its factorization.

21400104 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 910 (or 906 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 12.

The square root of 21400104 is about 4626.0246432547. The cubic root of 21400104 is about 277.6335596022.

Adding to 21400104 its reverse (40100412), we get a palindrome (61500516).

The spelling of 21400104 in words is "twenty-one million, four hundred thousand, one hundred four".