20553918 has 64 divisors (see below), whose sum is σ = 54286848. Its totient is φ = 5022720.

The previous prime is 20553893. The next prime is 20553931. The reversal of 20553918 is 81935502.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a congruent number.

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 6546 + ... + 9162.

It is an arithmetic number, because the mean of its divisors is an integer number (848232).

Almost surely, 2^20553918 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20553918, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27143424).

20553918 is an abundant number, since it is smaller than the sum of its proper divisors (33732930).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20553918 is a wasteful number, since it uses less digits than its factorization.

20553918 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2657.

The product of its (nonzero) digits is 10800, while the sum is 33.

The square root of 20553918 is about 4533.6429060966. The cubic root of 20553918 is about 273.9249177124.

The spelling of 20553918 in words is "twenty million, five hundred fifty-three thousand, nine hundred eighteen".