20535978 has 16 divisors (see below), whose sum is σ = 41133600. Its totient is φ = 6835056.

The previous prime is 20535947. The next prime is 20536013. The reversal of 20535978 is 87953502.

It is a Curzon number.

It is an unprimeable number.

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, 2548 + ... + 6896.

It is an arithmetic number, because the mean of its divisors is an integer number (2570850).

Almost surely, 2^20535978 is an apocalyptic number.

20535978 is an abundant number, since it is smaller than the sum of its proper divisors (20597622).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20535978 is a wasteful number, since it uses less digits than its factorization.

20535978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5141.

The product of its (nonzero) digits is 75600, while the sum is 39.

The square root of 20535978 is about 4531.6639328176. The cubic root of 20535978 is about 273.8451982242.

The spelling of 20535978 in words is "twenty million, five hundred thirty-five thousand, nine hundred seventy-eight".