20715971 has 4 divisors (see below), whose sum is σ = 20763600. Its totient is φ = 20668344.

The previous prime is 20715941. The next prime is 20715973. The reversal of 20715971 is 17951702.

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

It is a cyclic number.

It is not a de Polignac number, because 20715971 - 2¹⁴ = 20699587 is a prime.

It is a super-3 number, since 3×20715971³ (a number of 23 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20715973) 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, 23156 + ... + 24033.

It is an arithmetic number, because the mean of its divisors is an integer number (5190900).

Almost surely, 2^20715971 is an apocalyptic number.

20715971 is a deficient number, since it is larger than the sum of its proper divisors (47629).

20715971 is an equidigital number, since it uses as much as digits as its factorization.

20715971 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47628.

The product of its (nonzero) digits is 4410, while the sum is 32.

The square root of 20715971 is about 4551.4800889381. The cubic root of 20715971 is about 274.6429349279.

The spelling of 20715971 in words is "twenty million, seven hundred fifteen thousand, nine hundred seventy-one".