21342641 has 2 divisors, whose sum is σ = 21342642. Its totient is φ = 21342640.

The previous prime is 21342631. The next prime is 21342677. The reversal of 21342641 is 14624312.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16810000 + 4532641 = 4100^2 + 2129^2 .

It is a cyclic number.

It is not a de Polignac number, because 21342641 - 2¹⁸ = 21080497 is a prime.

It is not a weakly prime, because it can be changed into another prime (21342631) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10671320 + 10671321.

It is an arithmetic number, because the mean of its divisors is an integer number (10671321).

Almost surely, 2^21342641 is an apocalyptic number.

It is an amenable number.

21342641 is a deficient number, since it is larger than the sum of its proper divisors (1).

21342641 is an equidigital number, since it uses as much as digits as its factorization.

21342641 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1152, while the sum is 23.

The square root of 21342641 is about 4619.8096281124. The cubic root of 21342641 is about 277.3848387233.

Adding to 21342641 its reverse (14624312), we get a palindrome (35966953).

The spelling of 21342641 in words is "twenty-one million, three hundred forty-two thousand, six hundred forty-one".