21724445572557 has 48 divisors (see below), whose sum is σ = 36288289154880. Its totient is φ = 11458636697088.

The previous prime is 21724445572553. The next prime is 21724445572559. The reversal of 21724445572557 is 75527554442712.

It is not a de Polignac number, because 21724445572557 - 2² = 21724445572553 is a prime.

It is a super-3 number, since 3×21724445572557³ (a number of 41 digits) contains 333 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21724445572557.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21724445572553) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 57253653 + ... + 57631845.

It is an arithmetic number, because the mean of its divisors is an integer number (756006024060).

Almost surely, 2^{21724445572557} is an apocalyptic number.

It is an amenable number.

21724445572557 is a deficient number, since it is larger than the sum of its proper divisors (14563843582323).

21724445572557 is a wasteful number, since it uses less digits than its factorization.

21724445572557 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 408282 (or 408275 counting only the distinct ones).

The product of its digits is 109760000, while the sum is 60.

The spelling of 21724445572557 in words is "twenty-one trillion, seven hundred twenty-four billion, four hundred forty-five million, five hundred seventy-two thousand, five hundred fifty-seven".