97821817 has 2 divisors, whose sum is σ = 97821818. Its totient is φ = 97821816.

The previous prime is 97821803. The next prime is 97821839. The reversal of 97821817 is 71812879.

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., 77246521 + 20575296 = 8789^2 + 4536^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-97821817 is a prime.

It is not a weakly prime, because it can be changed into another prime (97801817) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 48910908 + 48910909.

It is an arithmetic number, because the mean of its divisors is an integer number (48910909).

Almost surely, 2^97821817 is an apocalyptic number.

It is an amenable number.

97821817 is a deficient number, since it is larger than the sum of its proper divisors (1).

97821817 is an equidigital number, since it uses as much as digits as its factorization.

97821817 is an evil number, because the sum of its binary digits is even.

The product of its digits is 56448, while the sum is 43.

The square root of 97821817 is about 9890.4912415916. The cubic root of 97821817 is about 460.7640374520.

The spelling of 97821817 in words is "ninety-seven million, eight hundred twenty-one thousand, eight hundred seventeen".