20128431 has 8 divisors (see below), whose sum is σ = 26903344. Its totient is φ = 13386240.

The previous prime is 20128421. The next prime is 20128439. The reversal of 20128431 is 13482102.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 20128431 - 2⁵ = 20128399 is a prime.

It is a super-2 number, since 2×20128431² = 810307469043522, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20128398 and 20128407.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20128439) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6706 + ... + 9231.

It is an arithmetic number, because the mean of its divisors is an integer number (3362918).

Almost surely, 2^20128431 is an apocalyptic number.

20128431 is a deficient number, since it is larger than the sum of its proper divisors (6774913).

20128431 is a wasteful number, since it uses less digits than its factorization.

20128431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16361.

The product of its (nonzero) digits is 384, while the sum is 21.

The square root of 20128431 is about 4486.4719992439. The cubic root of 20128431 is about 272.0215479974.

The spelling of 20128431 in words is "twenty million, one hundred twenty-eight thousand, four hundred thirty-one".