99766621 has 2 divisors, whose sum is σ = 99766622. Its totient is φ = 99766620.

The previous prime is 99766619. The next prime is 99766631. The reversal of 99766621 is 12666799.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 96924025 + 2842596 = 9845^2 + 1686^2 .

It is a cyclic number.

It is not a de Polignac number, because 99766621 - 2¹ = 99766619 is a prime.

Together with 99766619, it forms a pair of twin primes.

It is a nialpdrome in base 10.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (99766631) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 49883310 + 49883311.

It is an arithmetic number, because the mean of its divisors is an integer number (49883311).

Almost surely, 2^99766621 is an apocalyptic number.

It is an amenable number.

99766621 is a deficient number, since it is larger than the sum of its proper divisors (1).

99766621 is an equidigital number, since it uses as much as digits as its factorization.

99766621 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 244944, while the sum is 46.

The square root of 99766621 is about 9988.3242338242. The cubic root of 99766621 is about 463.7975189790.

The spelling of 99766621 in words is "ninety-nine million, seven hundred sixty-six thousand, six hundred twenty-one".