998778905 has 16 divisors (see below), whose sum is σ = 1247145984. Its totient is φ = 767257920.

The previous prime is 998778899. The next prime is 998778953. The reversal of 998778905 is 509877899.

It is not a de Polignac number, because 998778905 - 2¹⁰ = 998777881 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 27641 + ... + 52550.

It is an arithmetic number, because the mean of its divisors is an integer number (77946624).

Almost surely, 2^998778905 is an apocalyptic number.

It is an amenable number.

998778905 is a deficient number, since it is larger than the sum of its proper divisors (248367079).

998778905 is a wasteful number, since it uses less digits than its factorization.

998778905 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 80296.

The product of its (nonzero) digits is 11430720, while the sum is 62.

The square root of 998778905 is about 31603.4634969017. The cubic root of 998778905 is about 999.5928025461.

The spelling of 998778905 in words is "nine hundred ninety-eight million, seven hundred seventy-eight thousand, nine hundred five".