21448724 has 12 divisors (see below), whose sum is σ = 40947648. Its totient is φ = 9749400.

The previous prime is 21448723. The next prime is 21448793. The reversal of 21448724 is 42784412.

It is a super-2 number, since 2×21448724² = 920095522456352, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21448723) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 243692 + ... + 243779.

It is an arithmetic number, because the mean of its divisors is an integer number (3412304).

Almost surely, 2^21448724 is an apocalyptic number.

It is an amenable number.

21448724 is a deficient number, since it is larger than the sum of its proper divisors (19498924).

21448724 is a wasteful number, since it uses less digits than its factorization.

21448724 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 487486 (or 487484 counting only the distinct ones).

The product of its digits is 14336, while the sum is 32.

The square root of 21448724 is about 4631.2767138231. The cubic root of 21448724 is about 277.8436572396.

The spelling of 21448724 in words is "twenty-one million, four hundred forty-eight thousand, seven hundred twenty-four".