99993881 has 16 divisors (see below), whose sum is σ = 116185104. Its totient is φ = 85223424.

The previous prime is 99993841. The next prime is 99993889. The reversal of 99993881 is 18839999.

It can be written as a sum of positive squares in 8 ways, for example, as 7929856 + 92064025 = 2816^2 + 9595^2 .

It is a de Polignac number, because none of the positive numbers 2^k-99993881 is a prime.

It is a super-2 number, since 2×99993881² = 19997552474884322, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (99993889) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7445 + ... + 15981.

It is an arithmetic number, because the mean of its divisors is an integer number (7261569).

Almost surely, 2^99993881 is an apocalyptic number.

It is an amenable number.

99993881 is a deficient number, since it is larger than the sum of its proper divisors (16191223).

99993881 is a wasteful number, since it uses less digits than its factorization.

99993881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8620.

The product of its digits is 1259712, while the sum is 56.

The square root of 99993881 is about 9999.6940453196. The cubic root of 99993881 is about 464.1494158741.

The spelling of 99993881 in words is "ninety-nine million, nine hundred ninety-three thousand, eight hundred eighty-one".