20878559 has 8 divisors (see below), whose sum is σ = 22522752. Its totient is φ = 19239840.

The previous prime is 20878541. The next prime is 20878577. The reversal of 20878559 is 95587802.

It is an interprime number because it is at equal distance from previous prime (20878541) and next prime (20878577).

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 20878559 - 2⁸ = 20878303 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20878519) 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, 10289 + ... + 12149.

It is an arithmetic number, because the mean of its divisors is an integer number (2815344).

Almost surely, 2^20878559 is an apocalyptic number.

20878559 is a deficient number, since it is larger than the sum of its proper divisors (1644193).

20878559 is a wasteful number, since it uses less digits than its factorization.

20878559 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2737.

The product of its (nonzero) digits is 201600, while the sum is 44.

The square root of 20878559 is about 4569.3061836563. The cubic root of 20878559 is about 275.3595693187.

The spelling of 20878559 in words is "twenty million, eight hundred seventy-eight thousand, five hundred fifty-nine".