21620452146065 has 4 divisors (see below), whose sum is σ = 25944542575284. Its totient is φ = 17296361716848.

The previous prime is 21620452146037. The next prime is 21620452146077. The reversal of 21620452146065 is 56064125402612.

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 11817691909969 + 9802760236096 = 3437687^2 + 3130936^2 .

It is a cyclic number.

It is not a de Polignac number, because 21620452146065 - 2¹⁰ = 21620452145041 is a prime.

It is a Duffinian number.

It is a zygodrome in base 3.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2162045214602 + ... + 2162045214611.

It is an arithmetic number, because the mean of its divisors is an integer number (6486135643821).

Almost surely, 2^{21620452146065} is an apocalyptic number.

It is an amenable number.

21620452146065 is a deficient number, since it is larger than the sum of its proper divisors (4324090429219).

21620452146065 is an equidigital number, since it uses as much as digits as its factorization.

21620452146065 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4324090429218.

The product of its (nonzero) digits is 691200, while the sum is 44.

Adding to 21620452146065 its reverse (56064125402612), we get a palindrome (77684577548677).

The spelling of 21620452146065 in words is "twenty-one trillion, six hundred twenty billion, four hundred fifty-two million, one hundred forty-six thousand, sixty-five".