20478845 has 8 divisors (see below), whose sum is σ = 24607800. Its totient is φ = 16360960.

The previous prime is 20478823. The next prime is 20478869. The reversal of 20478845 is 54887402.

It can be written as a sum of positive squares in 4 ways, for example, as 4108729 + 16370116 = 2027^2 + 4046^2 .

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

It is not a de Polignac number, because 20478845 - 2²⁴ = 3701629 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20478799 and 20478808.

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, 2081 + ... + 6729.

It is an arithmetic number, because the mean of its divisors is an integer number (3075975).

Almost surely, 2^20478845 is an apocalyptic number.

It is an amenable number.

20478845 is a deficient number, since it is larger than the sum of its proper divisors (4128955).

20478845 is an equidigital number, since it uses as much as digits as its factorization.

20478845 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5535.

The product of its (nonzero) digits is 71680, while the sum is 38.

The square root of 20478845 is about 4525.3557871177. The cubic root of 20478845 is about 273.5910080846.

The spelling of 20478845 in words is "twenty million, four hundred seventy-eight thousand, eight hundred forty-five".