20845545 has 16 divisors (see below), whose sum is σ = 38117760. Its totient is φ = 9529344.

The previous prime is 20845543. The next prime is 20845579. The reversal of 20845545 is 54554802.

It is not a de Polignac number, because 20845545 - 2¹ = 20845543 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20845543) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 99160 + ... + 99369.

It is an arithmetic number, because the mean of its divisors is an integer number (2382360).

Almost surely, 2^20845545 is an apocalyptic number.

It is an amenable number.

20845545 is a deficient number, since it is larger than the sum of its proper divisors (17272215).

20845545 is a wasteful number, since it uses less digits than its factorization.

20845545 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 198544.

The product of its (nonzero) digits is 32000, while the sum is 33.

The square root of 20845545 is about 4565.6921709638. The cubic root of 20845545 is about 275.2143562867.

It can be divided in two parts, 208 and 45545, that added together give a triangular number (45753 = T₃₀₂).

The spelling of 20845545 in words is "twenty million, eight hundred forty-five thousand, five hundred forty-five".