21755421445067 has 4 divisors (see below), whose sum is σ = 21885693429936. Its totient is φ = 21625149460200.

The previous prime is 21755421445013. The next prime is 21755421445157. The reversal of 21755421445067 is 76054412455712.

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 21755421445067 - 2⁴⁴ = 4163235400651 is a prime.

It is a super-2 number, since 2×21755421445067² (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 (21755421445007) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 65135992184 + ... + 65135992517.

It is an arithmetic number, because the mean of its divisors is an integer number (5471423357484).

Almost surely, 2^{21755421445067} is an apocalyptic number.

21755421445067 is a deficient number, since it is larger than the sum of its proper divisors (130271984869).

21755421445067 is a wasteful number, since it uses less digits than its factorization.

21755421445067 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 130271984868.

The product of its (nonzero) digits is 9408000, while the sum is 53.

The spelling of 21755421445067 in words is "twenty-one trillion, seven hundred fifty-five billion, four hundred twenty-one million, four hundred forty-five thousand, sixty-seven".