21260101 has 2 divisors, whose sum is σ = 21260102. Its totient is φ = 21260100.

The previous prime is 21260087. The next prime is 21260117. The reversal of 21260101 is 10106212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20930625 + 329476 = 4575^2 + 574^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21260101 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21260171) 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 as a sum of consecutive naturals, namely, 10630050 + 10630051.

It is an arithmetic number, because the mean of its divisors is an integer number (10630051).

Almost surely, 2^21260101 is an apocalyptic number.

It is an amenable number.

21260101 is a deficient number, since it is larger than the sum of its proper divisors (1).

21260101 is an equidigital number, since it uses as much as digits as its factorization.

21260101 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 24, while the sum is 13.

The square root of 21260101 is about 4610.8677057578. The cubic root of 21260101 is about 277.0267930137.

Adding to 21260101 its reverse (10106212), we get a palindrome (31366313).

The spelling of 21260101 in words is "twenty-one million, two hundred sixty thousand, one hundred one".