20478123 has 8 divisors (see below), whose sum is σ = 30338000. Its totient is φ = 13652064.

The previous prime is 20478121. The next prime is 20478173. The reversal of 20478123 is 32187402.

It is not a de Polignac number, because 20478123 - 2¹ = 20478121 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27), and also a Moran number because the ratio is a prime number: 758449 = 20478123 / (2 + 0 + 4 + 7 + 8 + 1 + 2 + 3).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20478121) 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, 379198 + ... + 379251.

It is an arithmetic number, because the mean of its divisors is an integer number (3792250).

Almost surely, 2^20478123 is an apocalyptic number.

20478123 is a deficient number, since it is larger than the sum of its proper divisors (9859877).

20478123 is an equidigital number, since it uses as much as digits as its factorization.

20478123 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 758458 (or 758452 counting only the distinct ones).

The product of its (nonzero) digits is 2688, while the sum is 27.

The square root of 20478123 is about 4525.2760136814. The cubic root of 20478123 is about 273.5877928149.

The spelling of 20478123 in words is "twenty million, four hundred seventy-eight thousand, one hundred twenty-three".