99999870 has 64 divisors (see below), whose sum is σ = 247199040. Its totient is φ = 25878528.

The previous prime is 99999847. The next prime is 99999931. The reversal of 99999870 is 7899999.

It is a nialpdrome in base 10.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 173022 + ... + 173598.

It is an arithmetic number, because the mean of its divisors is an integer number (3862485).

Almost surely, 2^99999870 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 99999870, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (123599520).

99999870 is an abundant number, since it is smaller than the sum of its proper divisors (147199170).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

99999870 is a wasteful number, since it uses less digits than its factorization.

99999870 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 749.

The product of its (nonzero) digits is 3306744, while the sum is 60.

The square root of 99999870 is about 9999.9934999979. The cubic root of 99999870 is about 464.1586822257.

The spelling of 99999870 in words is "ninety-nine million, nine hundred ninety-nine thousand, eight hundred seventy".