20391423 has 8 divisors (see below), whose sum is σ = 29280048. Its totient is φ = 12548544.

The previous prime is 20391421. The next prime is 20391431. The reversal of 20391423 is 32419302.

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

It is not a de Polignac number, because 20391423 - 2¹ = 20391421 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20391393 and 20391402.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20391421) 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 7 ways as a sum of consecutive naturals, for example, 261390 + ... + 261467.

It is an arithmetic number, because the mean of its divisors is an integer number (3660006).

Almost surely, 2^20391423 is an apocalyptic number.

20391423 is a deficient number, since it is larger than the sum of its proper divisors (8888625).

20391423 is a wasteful number, since it uses less digits than its factorization.

20391423 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 522873.

The product of its (nonzero) digits is 1296, while the sum is 24.

The square root of 20391423 is about 4515.6863265732. The cubic root of 20391423 is about 273.2011425373.

The spelling of 20391423 in words is "twenty million, three hundred ninety-one thousand, four hundred twenty-three".