21148597 has 2 divisors, whose sum is σ = 21148598. Its totient is φ = 21148596.

The previous prime is 21148573. The next prime is 21148601. The reversal of 21148597 is 79584112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20304036 + 844561 = 4506^2 + 919^2 .

It is a cyclic number.

It is not a de Polignac number, because 21148597 - 2¹¹ = 21146549 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21148297) 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, 10574298 + 10574299.

It is an arithmetic number, because the mean of its divisors is an integer number (10574299).

Almost surely, 2^21148597 is an apocalyptic number.

It is an amenable number.

21148597 is a deficient number, since it is larger than the sum of its proper divisors (1).

21148597 is an equidigital number, since it uses as much as digits as its factorization.

21148597 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 20160, while the sum is 37.

The square root of 21148597 is about 4598.7603764493. The cubic root of 21148597 is about 276.5416313767.

The spelling of 21148597 in words is "twenty-one million, one hundred forty-eight thousand, five hundred ninety-seven".