20553863 has 4 divisors (see below), whose sum is σ = 22422408. Its totient is φ = 18685320.

The previous prime is 20553853. The next prime is 20553887. The reversal of 20553863 is 36835502.

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 20553863 - 2⁴ = 20553847 is a prime.

It is a super-2 number, since 2×20553863² = 844922568445538, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20553823) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 934256 + ... + 934277.

It is an arithmetic number, because the mean of its divisors is an integer number (5605602).

Almost surely, 2^20553863 is an apocalyptic number.

20553863 is a deficient number, since it is larger than the sum of its proper divisors (1868545).

20553863 is a wasteful number, since it uses less digits than its factorization.

20553863 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1868544.

The product of its (nonzero) digits is 21600, while the sum is 32.

The square root of 20553863 is about 4533.6368403303. The cubic root of 20553863 is about 273.9246733813.

The spelling of 20553863 in words is "twenty million, five hundred fifty-three thousand, eight hundred sixty-three".