21535223545 has 16 divisors (see below), whose sum is σ = 28235184768. Its totient is φ = 15637747840.

The previous prime is 21535223539. The next prime is 21535223557. The reversal of 21535223545 is 54532253512.

It is not a de Polignac number, because 21535223545 - 2³ = 21535223537 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 267004 + ... + 338173.

It is an arithmetic number, because the mean of its divisors is an integer number (1764699048).

Almost surely, 2^21535223545 is an apocalyptic number.

It is an amenable number.

21535223545 is a deficient number, since it is larger than the sum of its proper divisors (6699961223).

21535223545 is a wasteful number, since it uses less digits than its factorization.

21535223545 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 605840.

The product of its digits is 180000, while the sum is 37.

The spelling of 21535223545 in words is "twenty-one billion, five hundred thirty-five million, two hundred twenty-three thousand, five hundred forty-five".