21122641 has 2 divisors, whose sum is σ = 21122642. Its totient is φ = 21122640.

The previous prime is 21122611. The next prime is 21122657. The reversal of 21122641 is 14622112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 10857025 + 10265616 = 3295^2 + 3204^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21122641 is a prime.

It is not a weakly prime, because it can be changed into another prime (21122611) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10561320 + 10561321.

It is an arithmetic number, because the mean of its divisors is an integer number (10561321).

Almost surely, 2^21122641 is an apocalyptic number.

It is an amenable number.

21122641 is a deficient number, since it is larger than the sum of its proper divisors (1).

21122641 is an equidigital number, since it uses as much as digits as its factorization.

21122641 is an evil number, because the sum of its binary digits is even.

The product of its digits is 192, while the sum is 19.

The square root of 21122641 is about 4595.9374451792. The cubic root of 21122641 is about 276.4284504549.

Adding to 21122641 its reverse (14622112), we get a palindrome (35744753).

It can be divided in two parts, 2112 and 2641, that added together give a triangular number (4753 = T₉₇).

The spelling of 21122641 in words is "twenty-one million, one hundred twenty-two thousand, six hundred forty-one".