21448628 has 12 divisors (see below), whose sum is σ = 39743172. Its totient is φ = 10093440.

The previous prime is 21448613. The next prime is 21448631. The reversal of 21448628 is 82684412.

It can be written as a sum of positive squares in 2 ways, for example, as 18215824 + 3232804 = 4268^2 + 1798^2 .

It is a super-4 number, since 4×21448628⁴ (a number of 30 digits) contains 4444 as substring.

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 in 3 ways as a sum of consecutive naturals, for example, 157643 + ... + 157778.

It is an arithmetic number, because the mean of its divisors is an integer number (3311931).

Almost surely, 2^21448628 is an apocalyptic number.

It is an amenable number.

21448628 is a deficient number, since it is larger than the sum of its proper divisors (18294544).

21448628 is a wasteful number, since it uses less digits than its factorization.

21448628 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 315442 (or 315440 counting only the distinct ones).

The product of its digits is 24576, while the sum is 35.

The square root of 21448628 is about 4631.2663494988. The cubic root of 21448628 is about 277.8432427156.

The spelling of 21448628 in words is "twenty-one million, four hundred forty-eight thousand, six hundred twenty-eight".