20820475 has 12 divisors (see below), whose sum is σ = 27803776. Its totient is φ = 15374880.

The previous prime is 20820473. The next prime is 20820491. The reversal of 20820475 is 57402802.

It is not a de Polignac number, because 20820475 - 2¹ = 20820473 is a prime.

It is a hoax number, since the sum of its digits (28) coincides with the sum of the digits of its distinct prime factors.

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 11 ways as a sum of consecutive naturals, for example, 31707 + ... + 32356.

Almost surely, 2^20820475 is an apocalyptic number.

20820475 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

20820475 is a deficient number, since it is larger than the sum of its proper divisors (6983301).

20820475 is a wasteful number, since it uses less digits than its factorization.

20820475 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 64086 (or 64081 counting only the distinct ones).

The product of its (nonzero) digits is 4480, while the sum is 28.

The square root of 20820475 is about 4562.9458686248. The cubic root of 20820475 is about 275.1039827158.

The spelling of 20820475 in words is "twenty million, eight hundred twenty thousand, four hundred seventy-five".