99687421 has 2 divisors, whose sum is σ = 99687422. Its totient is φ = 99687420.

The previous prime is 99687409. The next prime is 99687437. The reversal of 99687421 is 12478699.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 89984196 + 9703225 = 9486^2 + 3115^2 .

It is an emirp because it is prime and its reverse (12478699) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-99687421 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (99607421) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 49843710 + 49843711.

It is an arithmetic number, because the mean of its divisors is an integer number (49843711).

Almost surely, 2^99687421 is an apocalyptic number.

It is an amenable number.

99687421 is a deficient number, since it is larger than the sum of its proper divisors (1).

99687421 is an equidigital number, since it uses as much as digits as its factorization.

99687421 is an evil number, because the sum of its binary digits is even.

The product of its digits is 217728, while the sum is 46.

The square root of 99687421 is about 9984.3588176708. The cubic root of 99687421 is about 463.6747575198.

The spelling of 99687421 in words is "ninety-nine million, six hundred eighty-seven thousand, four hundred twenty-one".