21543412554 has 24 divisors (see below), whose sum is σ = 49423123620. Its totient is φ = 6758717568.

The previous prime is 21543412531. The next prime is 21543412573. The reversal of 21543412554 is 45521434512.

21543412554 is a `hidden beast` number, since 2 + 1 + 543 + 41 + 25 + 54 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 20654001225 + 889411329 = 143715^2 + 29823^2 .

It is an unprimeable number.

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 11 ways as a sum of consecutive naturals, for example, 35201349 + ... + 35201960.

Almost surely, 2^21543412554 is an apocalyptic number.

21543412554 is an abundant number, since it is smaller than the sum of its proper divisors (27879711066).

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

21543412554 is a wasteful number, since it uses less digits than its factorization.

21543412554 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 70403334 (or 70403331 counting only the distinct ones).

The product of its digits is 96000, while the sum is 36.

The spelling of 21543412554 in words is "twenty-one billion, five hundred forty-three million, four hundred twelve thousand, five hundred fifty-four".