20728571238 has 24 divisors (see below), whose sum is σ = 44930428608. Its totient is φ = 6906673872.

The previous prime is 20728571231. The next prime is 20728571239. The reversal of 20728571238 is 83217582702.

20728571238 is a `hidden beast` number, since 2 + 0 + 72 + 8 + 571 + 2 + 3 + 8 = 666.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 20728571193 and 20728571202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20728571231) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 192406 + ... + 280137.

It is an arithmetic number, because the mean of its divisors is an integer number (1872101192).

Almost surely, 2^20728571238 is an apocalyptic number.

20728571238 is an abundant number, since it is smaller than the sum of its proper divisors (24201857370).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20728571238 is a wasteful number, since it uses less digits than its factorization.

20728571238 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 474988 (or 474985 counting only the distinct ones).

The product of its (nonzero) digits is 376320, while the sum is 45.

The spelling of 20728571238 in words is "twenty billion, seven hundred twenty-eight million, five hundred seventy-one thousand, two hundred thirty-eight".