21620546204243 has 4 divisors (see below), whose sum is σ = 24709195662000. Its totient is φ = 18531896746488.

The previous prime is 21620546204219. The next prime is 21620546204293. The reversal of 21620546204243 is 34240264502612.

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 21620546204243 - 2²⁰ = 21620545155667 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21620546204243.

It is not an unprimeable number, because it can be changed into a prime (21620546204293) 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, 1544324728868 + ... + 1544324728881.

It is an arithmetic number, because the mean of its divisors is an integer number (6177298915500).

Almost surely, 2^{21620546204243} is an apocalyptic number.

21620546204243 is a deficient number, since it is larger than the sum of its proper divisors (3088649457757).

21620546204243 is an equidigital number, since it uses as much as digits as its factorization.

21620546204243 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3088649457756.

The product of its (nonzero) digits is 552960, while the sum is 41.

The spelling of 21620546204243 in words is "twenty-one trillion, six hundred twenty billion, five hundred forty-six million, two hundred four thousand, two hundred forty-three".