21607841 has 2 divisors, whose sum is σ = 21607842. Its totient is φ = 21607840.

The previous prime is 21607829. The next prime is 21607849. The reversal of 21607841 is 14870612.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17181025 + 4426816 = 4145^2 + 2104^2 .

It is a cyclic number.

It is not a de Polignac number, because 21607841 - 2¹⁰ = 21606817 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21607849) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10803920 + 10803921.

It is an arithmetic number, because the mean of its divisors is an integer number (10803921).

Almost surely, 2^21607841 is an apocalyptic number.

It is an amenable number.

21607841 is a deficient number, since it is larger than the sum of its proper divisors (1).

21607841 is an equidigital number, since it uses as much as digits as its factorization.

21607841 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2688, while the sum is 29.

The square root of 21607841 is about 4648.4234961974. The cubic root of 21607841 is about 278.5290247344.

It can be divided in two parts, 2160 and 7841, that added together give a palindrome (10001).

The spelling of 21607841 in words is "twenty-one million, six hundred seven thousand, eight hundred forty-one".