21601744545 has 16 divisors (see below), whose sum is σ = 34566904512. Its totient is φ = 11519559360.

The previous prime is 21601744531. The next prime is 21601744573. The reversal of 21601744545 is 54544710612.

It is not a de Polignac number, because 21601744545 - 2⁵ = 21601744513 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 51654 + ... + 214176.

It is an arithmetic number, because the mean of its divisors is an integer number (2160431532).

Almost surely, 2^21601744545 is an apocalyptic number.

It is an amenable number.

21601744545 is a deficient number, since it is larger than the sum of its proper divisors (12965159967).

21601744545 is a wasteful number, since it uses less digits than its factorization.

21601744545 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 171392.

The product of its (nonzero) digits is 134400, while the sum is 39.

The spelling of 21601744545 in words is "twenty-one billion, six hundred one million, seven hundred forty-four thousand, five hundred forty-five".