20800845 has 72 divisors (see below), whose sum is σ = 41205528. Its totient is φ = 9642240.

The previous prime is 20800841. The next prime is 20800853. The reversal of 20800845 is 54800802.

It can be written as a sum of positive squares in 4 ways, for example, as 2499561 + 18301284 = 1581^2 + 4278^2 .

It is not a de Polignac number, because 20800845 - 2² = 20800841 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20800841) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 562167 + ... + 562203.

It is an arithmetic number, because the mean of its divisors is an integer number (572299).

Almost surely, 2^20800845 is an apocalyptic number.

It is an amenable number.

20800845 is a deficient number, since it is larger than the sum of its proper divisors (20404683).

20800845 is a wasteful number, since it uses less digits than its factorization.

20800845 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 123 (or 89 counting only the distinct ones).

The product of its (nonzero) digits is 2560, while the sum is 27.

The square root of 20800845 is about 4560.7943387090. The cubic root of 20800845 is about 275.0174975092.

It can be divided in two parts, 20800 and 845, that multiplied together give a cube (17576000 = 260³).

The spelling of 20800845 in words is "twenty million, eight hundred thousand, eight hundred forty-five".