20969287 has 4 divisors (see below), whose sum is σ = 20978496. Its totient is φ = 20960080.

The previous prime is 20969281. The next prime is 20969303. The reversal of 20969287 is 78296902.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 20969287 - 2⁷ = 20969159 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 (20969281) 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, 1587 + ... + 6667.

It is an arithmetic number, because the mean of its divisors is an integer number (5244624).

Almost surely, 2^20969287 is an apocalyptic number.

20969287 is a deficient number, since it is larger than the sum of its proper divisors (9209).

20969287 is an equidigital number, since it uses as much as digits as its factorization.

20969287 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9208.

The product of its (nonzero) digits is 108864, while the sum is 43.

The square root of 20969287 is about 4579.2234057753. The cubic root of 20969287 is about 275.7578522719.

It can be divided in two parts, 209 and 69287, that added together give a palindrome (69496).

The spelling of 20969287 in words is "twenty million, nine hundred sixty-nine thousand, two hundred eighty-seven".