20042405 has 8 divisors (see below), whose sum is σ = 25465752. Its totient is φ = 15090688.

The previous prime is 20042389. The next prime is 20042413. The reversal of 20042405 is 50424002.

It can be written as a sum of positive squares in 4 ways, for example, as 1800964 + 18241441 = 1342^2 + 4271^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 20042405 - 2⁴ = 20042389 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (17).

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 7 ways as a sum of consecutive naturals, for example, 117812 + ... + 117981.

It is an arithmetic number, because the mean of its divisors is an integer number (3183219).

Almost surely, 2^20042405 is an apocalyptic number.

It is an amenable number.

20042405 is a deficient number, since it is larger than the sum of its proper divisors (5423347).

20042405 is a wasteful number, since it uses less digits than its factorization.

20042405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 235815.

The product of its (nonzero) digits is 320, while the sum is 17.

The square root of 20042405 is about 4476.8744677509. The cubic root of 20042405 is about 271.6334677001.

Adding to 20042405 its reverse (50424002), we get a palindrome (70466407).

The spelling of 20042405 in words is "twenty million, forty-two thousand, four hundred five".