21448397 has 8 divisors (see below), whose sum is σ = 23559360. Its totient is φ = 19435680.

The previous prime is 21448379. The next prime is 21448433. The reversal of 21448397 is 79384412.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21448397 - 2⁶ = 21448333 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21448397.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21448307) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 24104 + ... + 24977.

It is an arithmetic number, because the mean of its divisors is an integer number (2944920).

Almost surely, 2^21448397 is an apocalyptic number.

It is an amenable number.

21448397 is a deficient number, since it is larger than the sum of its proper divisors (2110963).

21448397 is a wasteful number, since it uses less digits than its factorization.

21448397 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 49123.

The product of its digits is 48384, while the sum is 38.

The square root of 21448397 is about 4631.2414102484. The cubic root of 21448397 is about 277.8422452622.

The spelling of 21448397 in words is "twenty-one million, four hundred forty-eight thousand, three hundred ninety-seven".