21442263 has 8 divisors (see below), whose sum is σ = 29129328. Its totient is φ = 14025024.

The previous prime is 21442261. The next prime is 21442273. The reversal of 21442263 is 36224412.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21442263 - 2¹ = 21442261 is a prime.

It is a super-4 number, since 4×21442263⁴ (a number of 30 digits) contains 4444 as substring. Note that it is a super-d number also for d = 2.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21442261) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 67270 + ... + 67587.

It is an arithmetic number, because the mean of its divisors is an integer number (3641166).

Almost surely, 2^21442263 is an apocalyptic number.

21442263 is a deficient number, since it is larger than the sum of its proper divisors (7687065).

21442263 is a wasteful number, since it uses less digits than its factorization.

21442263 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 134913.

The product of its digits is 2304, while the sum is 24.

The square root of 21442263 is about 4630.5791214491. The cubic root of 21442263 is about 277.8157561525.

Adding to 21442263 its reverse (36224412), we get a palindrome (57666675).

The spelling of 21442263 in words is "twenty-one million, four hundred forty-two thousand, two hundred sixty-three".