20891488 has 24 divisors (see below), whose sum is σ = 43296120. Its totient is φ = 9895680.

The previous prime is 20891473. The next prime is 20891503. The reversal of 20891488 is 88419802.

It is an interprime number because it is at equal distance from previous prime (20891473) and next prime (20891503).

It is a self number, because there is not a number n which added to its sum of digits gives 20891488.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16573 + ... + 17788.

It is an arithmetic number, because the mean of its divisors is an integer number (1804005).

Almost surely, 2^20891488 is an apocalyptic number.

It is an amenable number.

20891488 is an abundant number, since it is smaller than the sum of its proper divisors (22404632).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20891488 is a wasteful number, since it uses less digits than its factorization.

20891488 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34390 (or 34382 counting only the distinct ones).

The product of its (nonzero) digits is 36864, while the sum is 40.

The square root of 20891488 is about 4570.7207309132. The cubic root of 20891488 is about 275.4163961853.

The spelling of 20891488 in words is "twenty million, eight hundred ninety-one thousand, four hundred eighty-eight".