21375065064061 has 4 divisors (see below), whose sum is σ = 21428906538172. Its totient is φ = 21321223589952.

The previous prime is 21375065064049. The next prime is 21375065064079. The reversal of 21375065064061 is 16046056057312.

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 4654072728900 + 16720992335161 = 2157330^2 + 4089131^2 .

It is a cyclic number.

It is not a de Polignac number, because 21375065064061 - 2¹⁵ = 21375065031293 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21375065064461) 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, 26920736460 + ... + 26920737253.

It is an arithmetic number, because the mean of its divisors is an integer number (5357226634543).

Almost surely, 2^{21375065064061} is an apocalyptic number.

It is an amenable number.

21375065064061 is a deficient number, since it is larger than the sum of its proper divisors (53841474111).

21375065064061 is an equidigital number, since it uses as much as digits as its factorization.

21375065064061 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53841474110.

The product of its (nonzero) digits is 907200, while the sum is 46.

The spelling of 21375065064061 in words is "twenty-one trillion, three hundred seventy-five billion, sixty-five million, sixty-four thousand, sixty-one".