20878045 has 8 divisors (see below), whose sum is σ = 25111224. Its totient is φ = 16664064.

The previous prime is 20878007. The next prime is 20878049. The reversal of 20878045 is 54087802.

It can be written as a sum of positive squares in 4 ways, for example, as 708964 + 20169081 = 842^2 + 4491^2 .

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 20878045 - 2¹⁵ = 20845277 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20878045.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20878049) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2284 + ... + 6853.

It is an arithmetic number, because the mean of its divisors is an integer number (3138903).

Almost surely, 2^20878045 is an apocalyptic number.

20878045 is the 2285-th decagonal number.

It is an amenable number.

20878045 is a deficient number, since it is larger than the sum of its proper divisors (4233179).

20878045 is an equidigital number, since it uses as much as digits as its factorization.

20878045 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9599.

The product of its (nonzero) digits is 17920, while the sum is 34.

The square root of 20878045 is about 4569.2499384472. The cubic root of 20878045 is about 275.3573096484.

The spelling of 20878045 in words is "twenty million, eight hundred seventy-eight thousand, forty-five".