20555623 has 4 divisors (see below), whose sum is σ = 22424328. Its totient is φ = 18686920.

The previous prime is 20555599. The next prime is 20555641. The reversal of 20555623 is 32655502.

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

It is a cyclic number.

It is not a de Polignac number, because 20555623 - 2¹³ = 20547431 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20555591 and 20555600.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20555323) 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, 934336 + ... + 934357.

It is an arithmetic number, because the mean of its divisors is an integer number (5606082).

Almost surely, 2^20555623 is an apocalyptic number.

20555623 is a deficient number, since it is larger than the sum of its proper divisors (1868705).

20555623 is a wasteful number, since it uses less digits than its factorization.

20555623 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1868704.

The product of its (nonzero) digits is 9000, while the sum is 28.

The square root of 20555623 is about 4533.8309408270. The cubic root of 20555623 is about 273.9324917602.

The spelling of 20555623 in words is "twenty million, five hundred fifty-five thousand, six hundred twenty-three".