99980905 has 4 divisors (see below), whose sum is σ = 119977092. Its totient is φ = 79984720.

The previous prime is 99980833. The next prime is 99980911. The reversal of 99980905 is 50908999.

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 44983849 + 54997056 = 6707^2 + 7416^2 .

It is a de Polignac number, because none of the positive numbers 2^k-99980905 is a prime.

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9998086 + ... + 9998095.

It is an arithmetic number, because the mean of its divisors is an integer number (29994273).

Almost surely, 2^99980905 is an apocalyptic number.

It is an amenable number.

99980905 is a deficient number, since it is larger than the sum of its proper divisors (19996187).

99980905 is a wasteful number, since it uses less digits than its factorization.

99980905 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19996186.

The product of its (nonzero) digits is 262440, while the sum is 49.

The square root of 99980905 is about 9999.0452044183. The cubic root of 99980905 is about 464.1293377677.

The spelling of 99980905 in words is "ninety-nine million, nine hundred eighty thousand, nine hundred five".