21108497 has 2 divisors, whose sum is σ = 21108498. Its totient is φ = 21108496.

The previous prime is 21108431. The next prime is 21108539. The reversal of 21108497 is 79480112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14737921 + 6370576 = 3839^2 + 2524^2 .

It is a cyclic number.

It is not a de Polignac number, because 21108497 - 2¹⁰ = 21107473 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21108097) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10554248 + 10554249.

It is an arithmetic number, because the mean of its divisors is an integer number (10554249).

Almost surely, 2^21108497 is an apocalyptic number.

It is an amenable number.

21108497 is a deficient number, since it is larger than the sum of its proper divisors (1).

21108497 is an equidigital number, since it uses as much as digits as its factorization.

21108497 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4032, while the sum is 32.

The square root of 21108497 is about 4594.3984372277. The cubic root of 21108497 is about 276.3667366283.

The spelling of 21108497 in words is "twenty-one million, one hundred eight thousand, four hundred ninety-seven".