99902881 has 4 divisors (see below), whose sum is σ = 107587732. Its totient is φ = 92218032.

The previous prime is 99902857. The next prime is 99902903. The reversal of 99902881 is 18820999.

It is a happy number.

It is the 4081-st star number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 18820999 = 31 ⋅607129.

It can be written as a sum of positive squares in 2 ways, for example, as 30747025 + 69155856 = 5545^2 + 8316^2 .

It is a cyclic number.

It is not a de Polignac number, because 99902881 - 2²³ = 91514273 is a prime.

It is a super-2 number, since 2×99902881² = 19961171264200322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (99902821) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3842406 + ... + 3842431.

It is an arithmetic number, because the mean of its divisors is an integer number (26896933).

Almost surely, 2^99902881 is an apocalyptic number.

It is an amenable number.

99902881 is a deficient number, since it is larger than the sum of its proper divisors (7684851).

99902881 is a wasteful number, since it uses less digits than its factorization.

99902881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7684850.

The product of its (nonzero) digits is 93312, while the sum is 46.

The square root of 99902881 is about 9995.1428704146. The cubic root of 99902881 is about 464.0085725353.

The spelling of 99902881 in words is "ninety-nine million, nine hundred two thousand, eight hundred eighty-one".