21545545127443 has 4 divisors (see below), whose sum is σ = 21754725177328. Its totient is φ = 21336365077560.

The previous prime is 21545545127419. The next prime is 21545545127521. The reversal of 21545545127443 is 34472154554512.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21545545127443 - 2⁵ = 21545545127411 is a prime.

It is a super-2 number, since 2×21545545127443² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21545545124443) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 104590024788 + ... + 104590024993.

It is an arithmetic number, because the mean of its divisors is an integer number (5438681294332).

Almost surely, 2^{21545545127443} is an apocalyptic number.

21545545127443 is a deficient number, since it is larger than the sum of its proper divisors (209180049885).

21545545127443 is a wasteful number, since it uses less digits than its factorization.

21545545127443 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 209180049884.

The product of its digits is 13440000, while the sum is 52.

The spelling of 21545545127443 in words is "twenty-one trillion, five hundred forty-five billion, five hundred forty-five million, one hundred twenty-seven thousand, four hundred forty-three".