97829981 has 2 divisors, whose sum is σ = 97829982. Its totient is φ = 97829980.

The previous prime is 97829929. The next prime is 97829989. The reversal of 97829981 is 18992879.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 95160025 + 2669956 = 9755^2 + 1634^2 .

It is an emirp because it is prime and its reverse (18992879) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 97829981 - 2¹⁰ = 97828957 is a prime.

It is a super-2 number, since 2×97829981² = 19141410364920722, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (97829989) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 48914990 + 48914991.

It is an arithmetic number, because the mean of its divisors is an integer number (48914991).

Almost surely, 2^97829981 is an apocalyptic number.

It is an amenable number.

97829981 is a deficient number, since it is larger than the sum of its proper divisors (1).

97829981 is an equidigital number, since it uses as much as digits as its factorization.

97829981 is an evil number, because the sum of its binary digits is even.

The product of its digits is 653184, while the sum is 53.

The square root of 97829981 is about 9890.9039526223. The cubic root of 97829981 is about 460.7768552231.

The spelling of 97829981 in words is "ninety-seven million, eight hundred twenty-nine thousand, nine hundred eighty-one".