99870581 has 4 divisors (see below), whose sum is σ = 99909612. Its totient is φ = 99831552.

The previous prime is 99870571. The next prime is 99870587. The reversal of 99870581 is 18507899.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 88078225 + 11792356 = 9385^2 + 3434^2 .

It is a cyclic number.

It is not a de Polignac number, because 99870581 - 2²⁶ = 32761717 is a prime.

It is a super-2 number, since 2×99870581² = 19948265898555122, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (99870587) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 15386 + ... + 20891.

It is an arithmetic number, because the mean of its divisors is an integer number (24977403).

Almost surely, 2^99870581 is an apocalyptic number.

It is an amenable number.

99870581 is a deficient number, since it is larger than the sum of its proper divisors (39031).

99870581 is a wasteful number, since it uses less digits than its factorization.

99870581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39030.

The product of its (nonzero) digits is 181440, while the sum is 47.

The square root of 99870581 is about 9993.5269549844. The cubic root of 99870581 is about 463.9585603226.

The spelling of 99870581 in words is "ninety-nine million, eight hundred seventy thousand, five hundred eighty-one".