20478405 has 16 divisors (see below), whose sum is σ = 33384960. Its totient is φ = 10715328.

The previous prime is 20478397. The next prime is 20478413. The reversal of 20478405 is 50487402.

It is an interprime number because it is at equal distance from previous prime (20478397) and next prime (20478413).

It is not a de Polignac number, because 20478405 - 2³ = 20478397 is a prime.

It is a congruent number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 12085 + ... + 13674.

It is an arithmetic number, because the mean of its divisors is an integer number (2086560).

Almost surely, 2^20478405 is an apocalyptic number.

It is an amenable number.

20478405 is a deficient number, since it is larger than the sum of its proper divisors (12906555).

20478405 is a wasteful number, since it uses less digits than its factorization.

20478405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25820.

The product of its (nonzero) digits is 8960, while the sum is 30.

The square root of 20478405 is about 4525.3071718945. The cubic root of 20478405 is about 273.5890486494.

The spelling of 20478405 in words is "twenty million, four hundred seventy-eight thousand, four hundred five".