21554434416 has 40 divisors (see below), whose sum is σ = 57478495744. Its totient is φ = 6953042880.

The previous prime is 21554434409. The next prime is 21554434417. The reversal of 21554434416 is 61443445512.

It is a super-2 number, since 2×21554434416² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21554434417) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7241266 + ... + 7244241.

Almost surely, 2^21554434416 is an apocalyptic number.

It is an amenable number.

21554434416 is an abundant number, since it is smaller than the sum of its proper divisors (35924061328).

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

21554434416 is a wasteful number, since it uses less digits than its factorization.

21554434416 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14485549 (or 14485543 counting only the distinct ones).

The product of its digits is 230400, while the sum is 39.

Adding to 21554434416 its reverse (61443445512), we get a palindrome (82997879928).

The spelling of 21554434416 in words is "twenty-one billion, five hundred fifty-four million, four hundred thirty-four thousand, four hundred sixteen".