97217521 has 2 divisors, whose sum is σ = 97217522. Its totient is φ = 97217520.

The previous prime is 97217513. The next prime is 97217551. The reversal of 97217521 is 12571279.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 72863296 + 24354225 = 8536^2 + 4935^2 .

It is a cyclic number.

It is not a de Polignac number, because 97217521 - 2³ = 97217513 is a prime.

It is not a weakly prime, because it can be changed into another prime (97217551) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 48608760 + 48608761.

It is an arithmetic number, because the mean of its divisors is an integer number (48608761).

Almost surely, 2^97217521 is an apocalyptic number.

It is an amenable number.

97217521 is a deficient number, since it is larger than the sum of its proper divisors (1).

97217521 is an equidigital number, since it uses as much as digits as its factorization.

97217521 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 8820, while the sum is 34.

The square root of 97217521 is about 9859.8945734729. The cubic root of 97217521 is about 459.8132843351.

It can be divided in two parts, 972175 and 21, that added together give a square (972196 = 986²).

The spelling of 97217521 in words is "ninety-seven million, two hundred seventeen thousand, five hundred twenty-one".