21442041 has 6 divisors (see below), whose sum is σ = 30971850. Its totient is φ = 14294688.

The previous prime is 21442037. The next prime is 21442063. The reversal of 21442041 is 14024412.

It can be written as a sum of positive squares in only one way, i.e., 21427641 + 14400 = 4629^2 + 120^2 .

It is not a de Polignac number, because 21442041 - 2² = 21442037 is a prime.

It is a super-2 number, since 2×21442041² = 919522244491362, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21442081) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1191216 + ... + 1191233.

It is an arithmetic number, because the mean of its divisors is an integer number (5161975).

Almost surely, 2^21442041 is an apocalyptic number.

It is an amenable number.

21442041 is a deficient number, since it is larger than the sum of its proper divisors (9529809).

21442041 is a wasteful number, since it uses less digits than its factorization.

21442041 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2382455 (or 2382452 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 18.

The square root of 21442041 is about 4630.5551503033. Note that the first 3 decimals coincide. The cubic root of 21442041 is about 277.8147973713.

Adding to 21442041 its reverse (14024412), we get a palindrome (35466453).

The spelling of 21442041 in words is "twenty-one million, four hundred forty-two thousand, forty-one".