21288654 has 12 divisors (see below), whose sum is σ = 46125456. Its totient is φ = 7096212.

The previous prime is 21288637. The next prime is 21288671. The reversal of 21288654 is 45688212.

It is an interprime number because it is at equal distance from previous prime (21288637) and next prime (21288671).

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 5 ways as a sum of consecutive naturals, for example, 591334 + ... + 591369.

It is an arithmetic number, because the mean of its divisors is an integer number (3843788).

Almost surely, 2^21288654 is an apocalyptic number.

21288654 is an abundant number, since it is smaller than the sum of its proper divisors (24836802).

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

21288654 is a wasteful number, since it uses less digits than its factorization.

21288654 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1182711 (or 1182708 counting only the distinct ones).

The product of its digits is 30720, while the sum is 36.

The square root of 21288654 is about 4613.9629387328. The cubic root of 21288654 is about 277.1507561682.

The spelling of 21288654 in words is "twenty-one million, two hundred eighty-eight thousand, six hundred fifty-four".