21112601 has 2 divisors, whose sum is σ = 21112602. Its totient is φ = 21112600.

The previous prime is 21112561. The next prime is 21112633. The reversal of 21112601 is 10621112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12082576 + 9030025 = 3476^2 + 3005^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21112601 is a prime.

It is not a weakly prime, because it can be changed into another prime (21172601) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10556300 + 10556301.

It is an arithmetic number, because the mean of its divisors is an integer number (10556301).

Almost surely, 2^21112601 is an apocalyptic number.

It is an amenable number.

21112601 is a deficient number, since it is larger than the sum of its proper divisors (1).

21112601 is an equidigital number, since it uses as much as digits as its factorization.

21112601 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 24, while the sum is 14.

The square root of 21112601 is about 4594.8450463536. The cubic root of 21112601 is about 276.3846462500.

Adding to 21112601 its reverse (10621112), we get a palindrome (31733713).

The spelling of 21112601 in words is "twenty-one million, one hundred twelve thousand, six hundred one".