21438153 has 24 divisors (see below), whose sum is σ = 34201440. Its totient is φ = 12831360.

The previous prime is 21438103. The next prime is 21438187. The reversal of 21438153 is 35183412.

It is a happy number.

It is not a de Polignac number, because 21438153 - 2⁶ = 21438089 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21438103) 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 23 ways as a sum of consecutive naturals, for example, 6913 + ... + 9521.

It is an arithmetic number, because the mean of its divisors is an integer number (1425060).

Almost surely, 2^21438153 is an apocalyptic number.

It is an amenable number.

21438153 is a deficient number, since it is larger than the sum of its proper divisors (12763287).

21438153 is a wasteful number, since it uses less digits than its factorization.

21438153 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2709 (or 2706 counting only the distinct ones).

The product of its digits is 2880, while the sum is 27.

The square root of 21438153 is about 4630.1353111977. The cubic root of 21438153 is about 277.7980046723.

It can be divided in two parts, 2143 and 8153, that added together give a triangular number (10296 = T₁₄₃).

The spelling of 21438153 in words is "twenty-one million, four hundred thirty-eight thousand, one hundred fifty-three".