20545815 has 32 divisors (see below), whose sum is σ = 33970176. Its totient is φ = 10598400.

The previous prime is 20545807. The next prime is 20545817. The reversal of 20545815 is 51854502.

It is not a de Polignac number, because 20545815 - 2³ = 20545807 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20545817) by changing a digit.

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 in 31 ways as a sum of consecutive naturals, for example, 106359 + ... + 106551.

It is an arithmetic number, because the mean of its divisors is an integer number (1061568).

Almost surely, 2^20545815 is an apocalyptic number.

20545815 is a deficient number, since it is larger than the sum of its proper divisors (13424361).

20545815 is a wasteful number, since it uses less digits than its factorization.

20545815 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 399.

The product of its (nonzero) digits is 8000, while the sum is 30.

The square root of 20545815 is about 4532.7491657933. The cubic root of 20545815 is about 273.8889163792. Note that the first 3 decimals are identical.

The spelling of 20545815 in words is "twenty million, five hundred forty-five thousand, eight hundred fifteen".