20071861 has 4 divisors (see below), whose sum is σ = 20346892. Its totient is φ = 19796832.

The previous prime is 20071829. The next prime is 20071873. The reversal of 20071861 is 16817002.

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

It can be written as a sum of positive squares in 2 ways, for example, as 13645636 + 6426225 = 3694^2 + 2535^2 .

It is a cyclic number.

It is not a de Polignac number, because 20071861 - 2⁵ = 20071829 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 (20071811) 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, 137406 + ... + 137551.

It is an arithmetic number, because the mean of its divisors is an integer number (5086723).

Almost surely, 2^20071861 is an apocalyptic number.

It is an amenable number.

20071861 is a deficient number, since it is larger than the sum of its proper divisors (275031).

20071861 is an equidigital number, since it uses as much as digits as its factorization.

20071861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 275030.

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

The square root of 20071861 is about 4480.1630550684. The cubic root of 20071861 is about 271.7664743404.

Adding to 20071861 its reverse (16817002), we get a palindrome (36888863).

The spelling of 20071861 in words is "twenty million, seventy-one thousand, eight hundred sixty-one".