99781906 has 16 divisors (see below), whose sum is σ = 171336960. Its totient is φ = 42693120.

The previous prime is 99781897. The next prime is 99781931. The reversal of 99781906 is 60918799.

It is a self number, because there is not a number n which added to its sum of digits gives 99781906.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3415 + ... + 14533.

It is an arithmetic number, because the mean of its divisors is an integer number (10708560).

Almost surely, 2^99781906 is an apocalyptic number.

99781906 is a deficient number, since it is larger than the sum of its proper divisors (71555054).

99781906 is a wasteful number, since it uses less digits than its factorization.

99781906 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11769.

The product of its (nonzero) digits is 244944, while the sum is 49.

The square root of 99781906 is about 9989.0893478835. The cubic root of 99781906 is about 463.8212035307.

The spelling of 99781906 in words is "ninety-nine million, seven hundred eighty-one thousand, nine hundred six".