20729547123 has 4 divisors (see below), whose sum is σ = 27639396168. Its totient is φ = 13819698080.

The previous prime is 20729547121. The next prime is 20729547161. The reversal of 20729547123 is 32174592702.

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 20729547123 - 2¹ = 20729547121 is a prime.

It is a super-3 number, since 3×20729547123³ (a number of 32 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (20729547121) 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, 3454924518 + ... + 3454924523.

It is an arithmetic number, because the mean of its divisors is an integer number (6909849042).

Almost surely, 2^20729547123 is an apocalyptic number.

20729547123 is a deficient number, since it is larger than the sum of its proper divisors (6909849045).

20729547123 is an equidigital number, since it uses as much as digits as its factorization.

20729547123 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6909849044.

The product of its (nonzero) digits is 211680, while the sum is 42.

The spelling of 20729547123 in words is "twenty billion, seven hundred twenty-nine million, five hundred forty-seven thousand, one hundred twenty-three".