20989267 has 4 divisors (see below), whose sum is σ = 22603840. Its totient is φ = 19374696.

The previous prime is 20989229. The next prime is 20989279. The reversal of 20989267 is 76298902.

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: 76298902 = 2 ⋅38149451.

It is a cyclic number.

It is not a de Polignac number, because 20989267 - 2¹⁵ = 20956499 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20989207) 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, 807267 + ... + 807292.

It is an arithmetic number, because the mean of its divisors is an integer number (5650960).

Almost surely, 2^20989267 is an apocalyptic number.

20989267 is a deficient number, since it is larger than the sum of its proper divisors (1614573).

20989267 is a wasteful number, since it uses less digits than its factorization.

20989267 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1614572.

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

The square root of 20989267 is about 4581.4044789780. The cubic root of 20989267 is about 275.8454071946.

The spelling of 20989267 in words is "twenty million, nine hundred eighty-nine thousand, two hundred sixty-seven".