21371841 has 6 divisors (see below), whose sum is σ = 30870450. Its totient is φ = 14247888.

The previous prime is 21371821. The next prime is 21371843. The reversal of 21371841 is 14817312.

It can be written as a sum of positive squares in only one way, i.e., 19184400 + 2187441 = 4380^2 + 1479^2 .

It is not a de Polignac number, because 21371841 - 2⁵ = 21371809 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21371843) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1187316 + ... + 1187333.

It is an arithmetic number, because the mean of its divisors is an integer number (5145075).

Almost surely, 2^21371841 is an apocalyptic number.

It is an amenable number.

21371841 is a deficient number, since it is larger than the sum of its proper divisors (9498609).

21371841 is a wasteful number, since it uses less digits than its factorization.

21371841 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2374655 (or 2374652 counting only the distinct ones).

The product of its digits is 1344, while the sum is 27.

The square root of 21371841 is about 4622.9688512903. The cubic root of 21371841 is about 277.5112827163.

The spelling of 21371841 in words is "twenty-one million, three hundred seventy-one thousand, eight hundred forty-one".