21354462062561 has 4 divisors (see below), whose sum is σ = 21355109808900. Its totient is φ = 21353814316224.

The previous prime is 21354462062477. The next prime is 21354462062569. The reversal of 21354462062561 is 16526026445312.

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

It can be written as a sum of positive squares in 2 ways, for example, as 16651549358161 + 4702912704400 = 4080631^2 + 2168620^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21354462062561 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21354462062569) 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, 323823716 + ... + 323889653.

It is an arithmetic number, because the mean of its divisors is an integer number (5338777452225).

Almost surely, 2^{21354462062561} is an apocalyptic number.

It is an amenable number.

21354462062561 is a deficient number, since it is larger than the sum of its proper divisors (647746339).

21354462062561 is an equidigital number, since it uses as much as digits as its factorization.

21354462062561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 647746338.

The product of its (nonzero) digits is 2073600, while the sum is 47.

The spelling of 21354462062561 in words is "twenty-one trillion, three hundred fifty-four billion, four hundred sixty-two million, sixty-two thousand, five hundred sixty-one".