21400452405 has 12 divisors (see below), whose sum is σ = 37094117580. Its totient is φ = 11413574592.

The previous prime is 21400452341. The next prime is 21400452407. The reversal of 21400452405 is 50425400412.

21400452405 is a `hidden beast` number, since 214 + 0 + 0 + 45 + 2 + 405 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 16859983716 + 4540468689 = 129846^2 + 67383^2 .

It is not a de Polignac number, because 21400452405 - 2⁶ = 21400452341 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21400452407) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 237782760 + ... + 237782849.

It is an arithmetic number, because the mean of its divisors is an integer number (3091176465).

Almost surely, 2^21400452405 is an apocalyptic number.

It is an amenable number.

21400452405 is a deficient number, since it is larger than the sum of its proper divisors (15693665175).

21400452405 is a wasteful number, since it uses less digits than its factorization.

21400452405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 475565620 (or 475565617 counting only the distinct ones).

The product of its (nonzero) digits is 6400, while the sum is 27.

Adding to 21400452405 its reverse (50425400412), we get a palindrome (71825852817).

The spelling of 21400452405 in words is "twenty-one billion, four hundred million, four hundred fifty-two thousand, four hundred five".