20878449 has 8 divisors (see below), whose sum is σ = 28363392. Its totient is φ = 13656240.

The previous prime is 20878447. The next prime is 20878453. The reversal of 20878449 is 94487802.

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

It is not a de Polignac number, because 20878449 - 2¹ = 20878447 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 20878449.

It is not an unprimeable number, because it can be changed into a prime (20878441) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 65497 + ... + 65814.

It is an arithmetic number, because the mean of its divisors is an integer number (3545424).

Almost surely, 2^20878449 is an apocalyptic number.

It is an amenable number.

20878449 is a deficient number, since it is larger than the sum of its proper divisors (7484943).

20878449 is a wasteful number, since it uses less digits than its factorization.

20878449 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 131367.

The product of its (nonzero) digits is 129024, while the sum is 42.

The square root of 20878449 is about 4569.2941468021. The cubic root of 20878449 is about 275.3590857348.

The spelling of 20878449 in words is "twenty million, eight hundred seventy-eight thousand, four hundred forty-nine".