20855101 has 4 divisors (see below), whose sum is σ = 21363804. Its totient is φ = 20346400.

The previous prime is 20855059. The next prime is 20855117. The reversal of 20855101 is 10155802.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 10155802 = 2 ⋅5077901.

It can be written as a sum of positive squares in 2 ways, for example, as 1265625 + 19589476 = 1125^2 + 4426^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20855101 is a prime.

It is a super-3 number, since 3×20855101³ (a number of 23 digits) contains 333 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 (20855201) 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, 254290 + ... + 254371.

It is an arithmetic number, because the mean of its divisors is an integer number (5340951).

Almost surely, 2^20855101 is an apocalyptic number.

It is an amenable number.

20855101 is a deficient number, since it is larger than the sum of its proper divisors (508703).

20855101 is an equidigital number, since it uses as much as digits as its factorization.

20855101 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 508702.

The product of its (nonzero) digits is 400, while the sum is 22.

The square root of 20855101 is about 4566.7385517457. The cubic root of 20855101 is about 275.2564043857.

The spelling of 20855101 in words is "twenty million, eight hundred fifty-five thousand, one hundred one".