20971869 has 8 divisors (see below), whose sum is σ = 28644672. Its totient is φ = 13640160.

The previous prime is 20971807. The next prime is 20971889. The reversal of 20971869 is 96817902.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a de Polignac number, because none of the positive numbers 2^k-20971869 is a prime.

It is a super-2 number, since 2×20971869² = 879638578706322, which contains 22 as substring.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 20971869.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20971889) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 85129 + ... + 85374.

It is an arithmetic number, because the mean of its divisors is an integer number (3580584).

Almost surely, 2^20971869 is an apocalyptic number.

It is an amenable number.

20971869 is a deficient number, since it is larger than the sum of its proper divisors (7672803).

20971869 is a wasteful number, since it uses less digits than its factorization.

20971869 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 170547.

The product of its (nonzero) digits is 54432, while the sum is 42.

The square root of 20971869 is about 4579.5053226304. The cubic root of 20971869 is about 275.7691700554.

The spelling of 20971869 in words is "twenty million, nine hundred seventy-one thousand, eight hundred sixty-nine".