21544061523 has 8 divisors (see below), whose sum is σ = 29048173200. Its totient is φ = 14201328768.

The previous prime is 21544061509. The next prime is 21544061593. The reversal of 21544061523 is 32516044512.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21544061523 - 2⁴ = 21544061507 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21544061593) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 40344418 + ... + 40344951.

It is an arithmetic number, because the mean of its divisors is an integer number (3631021650).

Almost surely, 2^21544061523 is an apocalyptic number.

21544061523 is a deficient number, since it is larger than the sum of its proper divisors (7504111677).

21544061523 is an equidigital number, since it uses as much as digits as its factorization.

21544061523 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 80689461.

The product of its (nonzero) digits is 28800, while the sum is 33.

The spelling of 21544061523 in words is "twenty-one billion, five hundred forty-four million, sixty-one thousand, five hundred twenty-three".