99999551 has 2 divisors, whose sum is σ = 99999552. Its totient is φ = 99999550.

The previous prime is 99999547. The next prime is 99999563. The reversal of 99999551 is 15599999.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 99999551 - 2² = 99999547 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

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 (99999541) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 49999775 + 49999776.

It is an arithmetic number, because the mean of its divisors is an integer number (49999776).

Almost surely, 2^99999551 is an apocalyptic number.

99999551 is a deficient number, since it is larger than the sum of its proper divisors (1).

99999551 is an equidigital number, since it uses as much as digits as its factorization.

99999551 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1476225, while the sum is 56.

The square root of 99999551 is about 9999.9775499748. The cubic root of 99999551 is about 464.1581886691.

The spelling of 99999551 in words is "ninety-nine million, nine hundred ninety-nine thousand, five hundred fifty-one".