20347871 has 4 divisors (see below), whose sum is σ = 20432544. Its totient is φ = 20263200.

The previous prime is 20347867. The next prime is 20347883. The reversal of 20347871 is 17874302.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 17874302 = 2 ⋅8937151.

It is a cyclic number.

It is not a de Polignac number, because 20347871 - 2² = 20347867 is a prime.

It is a Duffinian number.

It is a plaindrome in base 16.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20347771) 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, 41975 + ... + 42456.

It is an arithmetic number, because the mean of its divisors is an integer number (5108136).

Almost surely, 2^20347871 is an apocalyptic number.

20347871 is a deficient number, since it is larger than the sum of its proper divisors (84673).

20347871 is an equidigital number, since it uses as much as digits as its factorization.

20347871 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 84672.

The product of its (nonzero) digits is 9408, while the sum is 32.

The square root of 20347871 is about 4510.8614476616. The cubic root of 20347871 is about 273.0065029065.

The spelling of 20347871 in words is "twenty million, three hundred forty-seven thousand, eight hundred seventy-one".