21319097 has 2 divisors, whose sum is σ = 21319098. Its totient is φ = 21319096.

The previous prime is 21319093. The next prime is 21319127. The reversal of 21319097 is 79091312.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15649936 + 5669161 = 3956^2 + 2381^2 .

It is a cyclic number.

It is not a de Polignac number, because 21319097 - 2² = 21319093 is a prime.

It is not a weakly prime, because it can be changed into another prime (21319093) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10659548 + 10659549.

It is an arithmetic number, because the mean of its divisors is an integer number (10659549).

Almost surely, 2^21319097 is an apocalyptic number.

It is an amenable number.

21319097 is a deficient number, since it is larger than the sum of its proper divisors (1).

21319097 is an equidigital number, since it uses as much as digits as its factorization.

21319097 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3402, while the sum is 32.

The square root of 21319097 is about 4617.2607680312. The cubic root of 21319097 is about 277.2828027481.

The spelling of 21319097 in words is "twenty-one million, three hundred nineteen thousand, ninety-seven".