20871061 has 4 divisors (see below), whose sum is σ = 20963232. Its totient is φ = 20778892.

The previous prime is 20871049. The next prime is 20871077. The reversal of 20871061 is 16017802.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20871061 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20871001) 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, 45745 + ... + 46198.

It is an arithmetic number, because the mean of its divisors is an integer number (5240808).

Almost surely, 2^20871061 is an apocalyptic number.

It is an amenable number.

20871061 is a deficient number, since it is larger than the sum of its proper divisors (92171).

20871061 is an equidigital number, since it uses as much as digits as its factorization.

20871061 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 92170.

The product of its (nonzero) digits is 672, while the sum is 25.

The square root of 20871061 is about 4568.4856353063. The cubic root of 20871061 is about 275.3266025919.

Adding to 20871061 its reverse (16017802), we get a palindrome (36888863).

The spelling of 20871061 in words is "twenty million, eight hundred seventy-one thousand, sixty-one".