20970871 has 4 divisors (see below), whose sum is σ = 21882672. Its totient is φ = 20059072.

The previous prime is 20970869. The next prime is 20970893. The reversal of 20970871 is 17807902.

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 20970871 - 2¹ = 20970869 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 (20970811) 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, 455866 + ... + 455911.

It is an arithmetic number, because the mean of its divisors is an integer number (5470668).

Almost surely, 2^20970871 is an apocalyptic number.

20970871 is a deficient number, since it is larger than the sum of its proper divisors (911801).

20970871 is an equidigital number, since it uses as much as digits as its factorization.

20970871 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 911800.

The product of its (nonzero) digits is 7056, while the sum is 34.

The square root of 20970871 is about 4579.3963576000. The cubic root of 20970871 is about 275.7647955924.

The spelling of 20970871 in words is "twenty million, nine hundred seventy thousand, eight hundred seventy-one".