21103288 has 8 divisors (see below), whose sum is σ = 39568680. Its totient is φ = 10551640.

The previous prime is 21103267. The next prime is 21103301. The reversal of 21103288 is 88230112.

It is a tau number, because it is divible by the number of its divisors (8).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1318948 + ... + 1318963.

It is an arithmetic number, because the mean of its divisors is an integer number (4946085).

Almost surely, 2^21103288 is an apocalyptic number.

It is an amenable number.

21103288 is a deficient number, since it is larger than the sum of its proper divisors (18465392).

21103288 is a wasteful number, since it uses less digits than its factorization.

21103288 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2637917 (or 2637913 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 25.

The square root of 21103288 is about 4593.8315162835. The cubic root of 21103288 is about 276.3440015063.

The spelling of 21103288 in words is "twenty-one million, one hundred three thousand, two hundred eighty-eight".