21554331453 has 6 divisors (see below), whose sum is σ = 31134034334. Its totient is φ = 14369554296.

The previous prime is 21554331439. The next prime is 21554331457. The reversal of 21554331453 is 35413345512.

21554331453 is a `hidden beast` number, since 21 + 554 + 3 + 31 + 4 + 53 = 666.

It can be written as a sum of positive squares in only one way, i.e., 21473385444 + 80946009 = 146538^2 + 8997^2 .

It is not a de Polignac number, because 21554331453 - 2¹⁰ = 21554330429 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21554331457) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1197462850 + ... + 1197462867.

Almost surely, 2^21554331453 is an apocalyptic number.

It is an amenable number.

21554331453 is a deficient number, since it is larger than the sum of its proper divisors (9579702881).

21554331453 is a wasteful number, since it uses less digits than its factorization.

21554331453 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2394925723 (or 2394925720 counting only the distinct ones).

The product of its digits is 108000, while the sum is 36.

Adding to 21554331453 its reverse (35413345512), we get a palindrome (56967676965).

The spelling of 21554331453 in words is "twenty-one billion, five hundred fifty-four million, three hundred thirty-one thousand, four hundred fifty-three".