21508420548543 has 16 divisors (see below), whose sum is σ = 28745469338880. Its totient is φ = 14305162495104.

The previous prime is 21508420548533. The next prime is 21508420548551. The reversal of 21508420548543 is 34584502480512.

It is not a de Polignac number, because 21508420548543 - 2⁶ = 21508420548479 is a prime.

It is a super-2 number, since 2×21508420548543² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21508420548533) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 28205638 + ... + 28958156.

It is an arithmetic number, because the mean of its divisors is an integer number (1796591833680).

Almost surely, 2^{21508420548543} is an apocalyptic number.

21508420548543 is a deficient number, since it is larger than the sum of its proper divisors (7237048790337).

21508420548543 is a wasteful number, since it uses less digits than its factorization.

21508420548543 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 774958.

The product of its (nonzero) digits is 6144000, while the sum is 51.

The spelling of 21508420548543 in words is "twenty-one trillion, five hundred eight billion, four hundred twenty million, five hundred forty-eight thousand, five hundred forty-three".