21365100246065 has 4 divisors (see below), whose sum is σ = 25638120295284. Its totient is φ = 17092080196848.

The previous prime is 21365100246011. The next prime is 21365100246067. The reversal of 21365100246065 is 56064200156312.

It is a happy number.

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 2179237298176 + 19185862947889 = 1476224^2 + 4380167^2 .

It is a cyclic number.

It is not a de Polignac number, because 21365100246065 - 2⁶ = 21365100246001 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21365100246067) 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, 2136510024602 + ... + 2136510024611.

It is an arithmetic number, because the mean of its divisors is an integer number (6409530073821).

Almost surely, 2^{21365100246065} is an apocalyptic number.

It is an amenable number.

21365100246065 is a deficient number, since it is larger than the sum of its proper divisors (4273020049219).

21365100246065 is an equidigital number, since it uses as much as digits as its factorization.

21365100246065 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4273020049218.

The product of its (nonzero) digits is 259200, while the sum is 41.

The spelling of 21365100246065 in words is "twenty-one trillion, three hundred sixty-five billion, one hundred million, two hundred forty-six thousand, sixty-five".