21442153 has 4 divisors (see below), whose sum is σ = 21638980. Its totient is φ = 21245328.

The previous prime is 21442133. The next prime is 21442159. The reversal of 21442153 is 35124412.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 6411024 + 15031129 = 2532^2 + 3877^2 .

It is a cyclic number.

It is not a de Polignac number, because 21442153 - 2¹³ = 21433961 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21442159) 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 3 ways as a sum of consecutive naturals, for example, 98250 + ... + 98467.

It is an arithmetic number, because the mean of its divisors is an integer number (5409745).

Almost surely, 2^21442153 is an apocalyptic number.

It is an amenable number.

21442153 is a deficient number, since it is larger than the sum of its proper divisors (196827).

21442153 is a wasteful number, since it uses less digits than its factorization.

21442153 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 196826.

The product of its digits is 960, while the sum is 22.

The square root of 21442153 is about 4630.5672438698. The cubic root of 21442153 is about 277.8152810816.

Adding to 21442153 its reverse (35124412), we get a palindrome (56566565).

The spelling of 21442153 in words is "twenty-one million, four hundred forty-two thousand, one hundred fifty-three".