205065500072021 has 4 divisors (see below), whose sum is σ = 205066799996544. Its totient is φ = 205064200147500.

The previous prime is 205065500071987. The next prime is 205065500072057. The reversal of 205065500072021 is 120270005560502.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-205065500072021 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 (205065500072071) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 649725605 + ... + 650041146.

It is an arithmetic number, because the mean of its divisors is an integer number (51266699999136).

Almost surely, 2^{205065500072021} is an apocalyptic number.

It is an amenable number.

205065500072021 is a deficient number, since it is larger than the sum of its proper divisors (1299924523).

205065500072021 is a wasteful number, since it uses less digits than its factorization.

205065500072021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1299924522.

The product of its (nonzero) digits is 42000, while the sum is 35.

The spelling of 205065500072021 in words is "two hundred five trillion, sixty-five billion, five hundred million, seventy-two thousand, twenty-one".