20424455 has 4 divisors (see below), whose sum is σ = 24509352. Its totient is φ = 16339560.

The previous prime is 20424431. The next prime is 20424491. The reversal of 20424455 is 55442402.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 55442402 = 2 ⋅27721201.

It is not a de Polignac number, because 20424455 - 2⁸ = 20424199 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2042441 + ... + 2042450.

It is an arithmetic number, because the mean of its divisors is an integer number (6127338).

Almost surely, 2^20424455 is an apocalyptic number.

20424455 is a deficient number, since it is larger than the sum of its proper divisors (4084897).

20424455 is an equidigital number, since it uses as much as digits as its factorization.

20424455 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4084896.

The product of its (nonzero) digits is 6400, while the sum is 26.

The square root of 20424455 is about 4519.3423194089. The cubic root of 20424455 is about 273.3485821686.

Adding to 20424455 its reverse (55442402), we get a palindrome (75866857).

The spelling of 20424455 in words is "twenty million, four hundred twenty-four thousand, four hundred fifty-five".