20559878 has 4 divisors (see below), whose sum is σ = 30839820. Its totient is φ = 10279938.

The previous prime is 20559841. The next prime is 20559883. The reversal of 20559878 is 87895502.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 87895502 = 2 ⋅43947751.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5139968 + ... + 5139971.

It is an arithmetic number, because the mean of its divisors is an integer number (7709955).

Almost surely, 2^20559878 is an apocalyptic number.

20559878 is a deficient number, since it is larger than the sum of its proper divisors (10279942).

20559878 is a wasteful number, since it uses less digits than its factorization.

20559878 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10279941.

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

The square root of 20559878 is about 4534.3001665086. The cubic root of 20559878 is about 273.9513917360.

The spelling of 20559878 in words is "twenty million, five hundred fifty-nine thousand, eight hundred seventy-eight".