21404435361 has 32 divisors (see below), whose sum is σ = 31135373568. Its totient is φ = 13024880640.

The previous prime is 21404435341. The next prime is 21404435411. The reversal of 21404435361 is 16353440412.

It is a happy number.

It is not a de Polignac number, because 21404435361 - 2¹⁹ = 21403911073 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21404435321) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 568621 + ... + 605093.

It is an arithmetic number, because the mean of its divisors is an integer number (972980424).

Almost surely, 2^21404435361 is an apocalyptic number.

It is an amenable number.

21404435361 is a deficient number, since it is larger than the sum of its proper divisors (9730938207).

21404435361 is a wasteful number, since it uses less digits than its factorization.

21404435361 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36841.

The product of its (nonzero) digits is 34560, while the sum is 33.

Adding to 21404435361 its reverse (16353440412), we get a palindrome (37757875773).

The spelling of 21404435361 in words is "twenty-one billion, four hundred four million, four hundred thirty-five thousand, three hundred sixty-one".