21738097 has 2 divisors, whose sum is σ = 21738098. Its totient is φ = 21738096.

The previous prime is 21738089. The next prime is 21738103. The reversal of 21738097 is 79083712.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12952801 + 8785296 = 3599^2 + 2964^2 .

It is a cyclic number.

It is not a de Polignac number, because 21738097 - 2³ = 21738089 is a prime.

It is a super-2 number, since 2×21738097² = 945089722362818, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21738007) 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, 10869048 + 10869049.

It is an arithmetic number, because the mean of its divisors is an integer number (10869049).

Almost surely, 2^21738097 is an apocalyptic number.

It is an amenable number.

21738097 is a deficient number, since it is larger than the sum of its proper divisors (1).

21738097 is an equidigital number, since it uses as much as digits as its factorization.

21738097 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 21168, while the sum is 37.

The square root of 21738097 is about 4662.4132163505. The cubic root of 21738097 is about 279.0875784379.

The spelling of 21738097 in words is "twenty-one million, seven hundred thirty-eight thousand, ninety-seven".