99995551 has 2 divisors, whose sum is σ = 99995552. Its totient is φ = 99995550.

The previous prime is 99995549. The next prime is 99995563. The reversal of 99995551 is 15559999.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 99995551 - 2¹ = 99995549 is a prime.

It is a super-2 number, since 2×99995551² = 19998220439587202, which contains 22 as substring.

Together with 99995549, 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 (99995591) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 49997775 + 49997776.

It is an arithmetic number, because the mean of its divisors is an integer number (49997776).

Almost surely, 2^99995551 is an apocalyptic number.

99995551 is a deficient number, since it is larger than the sum of its proper divisors (1).

99995551 is an equidigital number, since it uses as much as digits as its factorization.

99995551 is an evil number, because the sum of its binary digits is even.

The product of its digits is 820125, while the sum is 52.

The square root of 99995551 is about 9999.7775475257. Note that the first 3 decimals coincide. The cubic root of 99995551 is about 464.1519997830.

The spelling of 99995551 in words is "ninety-nine million, nine hundred ninety-five thousand, five hundred fifty-one".