21438548 has 12 divisors (see below), whose sum is σ = 37620660. Its totient is φ = 10689792.

The previous prime is 21438541. The next prime is 21438589. The reversal of 21438548 is 84583412.

It can be written as a sum of positive squares in 2 ways, for example, as 12306064 + 9132484 = 3508^2 + 3022^2 .

It is a super-2 number, since 2×21438548² = 919222680696608, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21438541) 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, 5693 + ... + 8676.

It is an arithmetic number, because the mean of its divisors is an integer number (3135055).

Almost surely, 2^21438548 is an apocalyptic number.

It is an amenable number.

21438548 is a deficient number, since it is larger than the sum of its proper divisors (16182112).

21438548 is a wasteful number, since it uses less digits than its factorization.

21438548 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14746 (or 14744 counting only the distinct ones).

The product of its digits is 30720, while the sum is 35.

The square root of 21438548 is about 4630.1779663421. The cubic root of 21438548 is about 277.7997108133.

The spelling of 21438548 in words is "twenty-one million, four hundred thirty-eight thousand, five hundred forty-eight".