21543454102 has 16 divisors (see below), whose sum is σ = 34276238640. Its totient is φ = 10120269568.

The previous prime is 21543454087. The next prime is 21543454109. The reversal of 21543454102 is 20145434512.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21543454109) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 537448 + ... + 576139.

It is an arithmetic number, because the mean of its divisors is an integer number (2142264915).

Almost surely, 2^21543454102 is an apocalyptic number.

21543454102 is a deficient number, since it is larger than the sum of its proper divisors (12732784538).

21543454102 is a wasteful number, since it uses less digits than its factorization.

21543454102 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1114175.

The product of its (nonzero) digits is 19200, while the sum is 31.

Adding to 21543454102 its reverse (20145434512), we get a palindrome (41688888614).

The spelling of 21543454102 in words is "twenty-one billion, five hundred forty-three million, four hundred fifty-four thousand, one hundred two".