21440248 has 8 divisors (see below), whose sum is σ = 40200480. Its totient is φ = 10720120.

The previous prime is 21440239. The next prime is 21440257. The reversal of 21440248 is 84204412.

It is an interprime number because it is at equal distance from previous prime (21440239) and next prime (21440257).

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

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1340008 + ... + 1340023.

It is an arithmetic number, because the mean of its divisors is an integer number (5025060).

Almost surely, 2^21440248 is an apocalyptic number.

It is an amenable number.

21440248 is a deficient number, since it is larger than the sum of its proper divisors (18760232).

21440248 is a wasteful number, since it uses less digits than its factorization.

21440248 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2680037 (or 2680033 counting only the distinct ones).

The product of its (nonzero) digits is 2048, while the sum is 25.

The square root of 21440248 is about 4630.3615409598. The cubic root of 21440248 is about 277.8070534596.

The spelling of 21440248 in words is "twenty-one million, four hundred forty thousand, two hundred forty-eight".