97646821 has 2 divisors, whose sum is σ = 97646822. Its totient is φ = 97646820.

The previous prime is 97646819. The next prime is 97646831. The reversal of 97646821 is 12864679.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 67010596 + 30636225 = 8186^2 + 5535^2 .

It is an emirp because it is prime and its reverse (12864679) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 97646821 - 2¹ = 97646819 is a prime.

Together with 97646819, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (97646831) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 48823410 + 48823411.

It is an arithmetic number, because the mean of its divisors is an integer number (48823411).

Almost surely, 2^97646821 is an apocalyptic number.

It is an amenable number.

97646821 is a deficient number, since it is larger than the sum of its proper divisors (1).

97646821 is an equidigital number, since it uses as much as digits as its factorization.

97646821 is an evil number, because the sum of its binary digits is even.

The product of its digits is 145152, while the sum is 43.

The square root of 97646821 is about 9881.6406026530. The cubic root of 97646821 is about 460.4891158469.

The spelling of 97646821 in words is "ninety-seven million, six hundred forty-six thousand, eight hundred twenty-one".