20742550165 has 4 divisors (see below), whose sum is σ = 24891060204. Its totient is φ = 16594040128.

The previous prime is 20742550133. The next prime is 20742550177. The reversal of 20742550165 is 56105524702.

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 12207377169 + 8535172996 = 110487^2 + 92386^2 .

It is a cyclic number.

It is not a de Polignac number, because 20742550165 - 2⁵ = 20742550133 is a prime.

It is a Duffinian number.

It is a congruent number.

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, 2074255012 + ... + 2074255021.

It is an arithmetic number, because the mean of its divisors is an integer number (6222765051).

Almost surely, 2^20742550165 is an apocalyptic number.

It is an amenable number.

20742550165 is a deficient number, since it is larger than the sum of its proper divisors (4148510039).

20742550165 is an equidigital number, since it uses as much as digits as its factorization.

20742550165 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4148510038.

The product of its (nonzero) digits is 84000, while the sum is 37.

The spelling of 20742550165 in words is "twenty billion, seven hundred forty-two million, five hundred fifty thousand, one hundred sixty-five".