21207448 has 8 divisors (see below), whose sum is σ = 39763980. Its totient is φ = 10603720.

The previous prime is 21207437. The next prime is 21207467. The reversal of 21207448 is 84470212.

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

It is a hoax number, since the sum of its digits (28) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 1325458 + ... + 1325473.

Almost surely, 2^21207448 is an apocalyptic number.

It is an amenable number.

21207448 is a deficient number, since it is larger than the sum of its proper divisors (18556532).

21207448 is a wasteful number, since it uses less digits than its factorization.

21207448 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2650937 (or 2650933 counting only the distinct ones).

The product of its (nonzero) digits is 3584, while the sum is 28.

The square root of 21207448 is about 4605.1545033799. The cubic root of 21207448 is about 276.7979080889.

The spelling of 21207448 in words is "twenty-one million, two hundred seven thousand, four hundred forty-eight".