21120489 has 24 divisors (see below), whose sum is σ = 33210632. Its totient is φ = 12856320.

The previous prime is 21120479. The next prime is 21120499. The reversal of 21120489 is 98402112.

It is an interprime number because it is at equal distance from previous prime (21120479) and next prime (21120499).

It can be written as a sum of positive squares in 4 ways, for example, as 870489 + 20250000 = 933^2 + 4500^2 .

It is not a de Polignac number, because 21120489 - 2⁷ = 21120361 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21120469) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 10419 + ... + 12279.

Almost surely, 2^21120489 is an apocalyptic number.

It is an amenable number.

21120489 is a deficient number, since it is larger than the sum of its proper divisors (12090143).

21120489 is a wasteful number, since it uses less digits than its factorization.

21120489 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1977 (or 1974 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 27.

The square root of 21120489 is about 4595.7033194061. The cubic root of 21120489 is about 276.4190625154.

It can be divided in two parts, 21120 and 489, that added together give a square (21609 = 147²).

The spelling of 21120489 in words is "twenty-one million, one hundred twenty thousand, four hundred eighty-nine".