21404401004 has 48 divisors (see below), whose sum is σ = 45410383872. Its totient is φ = 8617819392.

The previous prime is 21404400977. The next prime is 21404401043. The reversal of 21404401004 is 40010440412.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 219269 + ... + 301475.

It is an arithmetic number, because the mean of its divisors is an integer number (946049664).

Almost surely, 2^21404401004 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21404401004, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22705191936).

21404401004 is an abundant number, since it is smaller than the sum of its proper divisors (24005982868).

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

21404401004 is a wasteful number, since it uses less digits than its factorization.

21404401004 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 82782 (or 82780 counting only the distinct ones).

The product of its (nonzero) digits is 512, while the sum is 20.

Adding to 21404401004 its reverse (40010440412), we get a palindrome (61414841416).

The spelling of 21404401004 in words is "twenty-one billion, four hundred four million, four hundred one thousand, four".