20218845 has 16 divisors (see below), whose sum is σ = 32437440. Its totient is φ = 10754304.

The previous prime is 20218843. The next prime is 20218859. The reversal of 20218845 is 54881202.

It is not a de Polignac number, because 20218845 - 2¹ = 20218843 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20218843) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4677 + ... + 7893.

It is an arithmetic number, because the mean of its divisors is an integer number (2027340).

Almost surely, 2^20218845 is an apocalyptic number.

It is an amenable number.

20218845 is a deficient number, since it is larger than the sum of its proper divisors (12218595).

20218845 is a wasteful number, since it uses less digits than its factorization.

20218845 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3644.

The product of its (nonzero) digits is 5120, while the sum is 30.

The square root of 20218845 is about 4496.5370008485. The cubic root of 20218845 is about 272.4282334928.

The spelling of 20218845 in words is "twenty million, two hundred eighteen thousand, eight hundred forty-five".