20845555 has 8 divisors (see below), whose sum is σ = 25142832. Its totient is φ = 16591008.

The previous prime is 20845543. The next prime is 20845579. The reversal of 20845555 is 55554802.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 20845555 - 2⁵ = 20845523 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20845555.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9597 + ... + 11566.

It is an arithmetic number, because the mean of its divisors is an integer number (3142854).

Almost surely, 2^20845555 is an apocalyptic number.

20845555 is a deficient number, since it is larger than the sum of its proper divisors (4297277).

20845555 is a wasteful number, since it uses less digits than its factorization.

20845555 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21365.

The product of its (nonzero) digits is 40000, while the sum is 34.

The square root of 20845555 is about 4565.6932660879. The cubic root of 20845555 is about 275.2144002952.

The spelling of 20845555 in words is "twenty million, eight hundred forty-five thousand, five hundred fifty-five".