21724061545 has 16 divisors (see below), whose sum is σ = 27316154880. Its totient is φ = 16554053824.

The previous prime is 21724061539. The next prime is 21724061587. The reversal of 21724061545 is 54516042712.

It is a cyclic number.

It is not a de Polignac number, because 21724061545 - 2³ = 21724061537 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, 367714 + ... + 422683.

It is an arithmetic number, because the mean of its divisors is an integer number (1707259680).

Almost surely, 2^21724061545 is an apocalyptic number.

It is an amenable number.

21724061545 is a deficient number, since it is larger than the sum of its proper divisors (5592093335).

21724061545 is a wasteful number, since it uses less digits than its factorization.

21724061545 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 790664.

The product of its (nonzero) digits is 67200, while the sum is 37.

The spelling of 21724061545 in words is "twenty-one billion, seven hundred twenty-four million, sixty-one thousand, five hundred forty-five".