20768555 has 4 divisors (see below), whose sum is σ = 24922272. Its totient is φ = 16614840.

The previous prime is 20768551. The next prime is 20768567. The reversal of 20768555 is 55586702.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 20768555 - 2² = 20768551 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20768551) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2076851 + ... + 2076860.

It is an arithmetic number, because the mean of its divisors is an integer number (6230568).

Almost surely, 2^20768555 is an apocalyptic number.

20768555 is a deficient number, since it is larger than the sum of its proper divisors (4153717).

20768555 is an equidigital number, since it uses as much as digits as its factorization.

20768555 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4153716.

The product of its (nonzero) digits is 84000, while the sum is 38.

The square root of 20768555 is about 4557.2530103122. The cubic root of 20768555 is about 274.8751168503.

The spelling of 20768555 in words is "twenty million, seven hundred sixty-eight thousand, five hundred fifty-five".