99981697 has 2 divisors, whose sum is σ = 99981698. Its totient is φ = 99981696.

The previous prime is 99981653. The next prime is 99981701. The reversal of 99981697 is 79618999.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 59582961 + 40398736 = 7719^2 + 6356^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-99981697 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (99984697) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 49990848 + 49990849.

It is an arithmetic number, because the mean of its divisors is an integer number (49990849).

Almost surely, 2^99981697 is an apocalyptic number.

It is an amenable number.

99981697 is a deficient number, since it is larger than the sum of its proper divisors (1).

99981697 is an equidigital number, since it uses as much as digits as its factorization.

99981697 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2204496, while the sum is 58.

The square root of 99981697 is about 9999.0848081212. The cubic root of 99981697 is about 464.1305632999.

The spelling of 99981697 in words is "ninety-nine million, nine hundred eighty-one thousand, six hundred ninety-seven".