21404420343 has 20 divisors (see below), whose sum is σ = 31978495648. Its totient is φ = 14267832480.

The previous prime is 21404420327. The next prime is 21404420347. The reversal of 21404420343 is 34302440412.

It is a happy number.

21404420343 is a `hidden beast` number, since 214 + 0 + 442 + 0 + 3 + 4 + 3 = 666.

It is not a de Polignac number, because 21404420343 - 2⁴ = 21404420327 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21404420347) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 1100955 + ... + 1120227.

Almost surely, 2^21404420343 is an apocalyptic number.

21404420343 is a deficient number, since it is larger than the sum of its proper divisors (10574075305).

21404420343 is a wasteful number, since it uses less digits than its factorization.

21404420343 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32996 (or 32987 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 27.

Adding to 21404420343 its reverse (34302440412), we get a palindrome (55706860755).

The spelling of 21404420343 in words is "twenty-one billion, four hundred four million, four hundred twenty thousand, three hundred forty-three".