21404401002 has 24 divisors (see below), whose sum is σ = 46687457700. Its totient is φ = 7086914880.

The previous prime is 21404400977. The next prime is 21404401043. The reversal of 21404401002 is 20010440412.

21404401002 is a `hidden beast` number, since 214 + 0 + 440 + 10 + 0 + 2 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 20678152401 + 726248601 = 143799^2 + 26949^2 .

It is a Harshad number since it is a multiple of its sum of digits (18).

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3987699 + ... + 3993062.

Almost surely, 2^21404401002 is an apocalyptic number.

21404401002 is an abundant number, since it is smaller than the sum of its proper divisors (25283056698).

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

21404401002 is a wasteful number, since it uses less digits than its factorization.

21404401002 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7980918 (or 7980915 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 18.

Adding to 21404401002 its reverse (20010440412), we get a palindrome (41414841414).

The spelling of 21404401002 in words is "twenty-one billion, four hundred four million, four hundred one thousand, two".