20878136 has 8 divisors (see below), whose sum is σ = 39146520. Its totient is φ = 10439064.

The previous prime is 20878133. The next prime is 20878163. The reversal of 20878136 is 63187802.

It is a tau number, because it is divible by the number of its divisors (8).

It is a junction number, because it is equal to n+sod(n) for n = 20878096 and 20878105.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20878133) 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 as a sum of consecutive naturals, namely, 1304876 + ... + 1304891.

It is an arithmetic number, because the mean of its divisors is an integer number (4893315).

Almost surely, 2^20878136 is an apocalyptic number.

It is an amenable number.

20878136 is a deficient number, since it is larger than the sum of its proper divisors (18268384).

20878136 is a wasteful number, since it uses less digits than its factorization.

20878136 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2609773 (or 2609769 counting only the distinct ones).

The product of its (nonzero) digits is 16128, while the sum is 35.

The square root of 20878136 is about 4569.2598963071. The cubic root of 20878136 is about 275.3577097095.

The spelling of 20878136 in words is "twenty million, eight hundred seventy-eight thousand, one hundred thirty-six".