20820478 has 16 divisors (see below), whose sum is σ = 37792224. Its totient is φ = 8398080.

The previous prime is 20820473. The next prime is 20820491. The reversal of 20820478 is 87402802.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20820473) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 43503 + ... + 43978.

It is an arithmetic number, because the mean of its divisors is an integer number (2362014).

Almost surely, 2^20820478 is an apocalyptic number.

20820478 is a deficient number, since it is larger than the sum of its proper divisors (16971746).

20820478 is a wasteful number, since it uses less digits than its factorization.

20820478 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 87507.

The product of its (nonzero) digits is 7168, while the sum is 31.

The square root of 20820478 is about 4562.9461973598. The cubic root of 20820478 is about 275.1039959289.

The spelling of 20820478 in words is "twenty million, eight hundred twenty thousand, four hundred seventy-eight".