99906778 has 8 divisors (see below), whose sum is σ = 151913268. Its totient is φ = 49269024.

The previous prime is 99906743. The next prime is 99906809. The reversal of 99906778 is 87760999.

It can be written as a sum of positive squares in 2 ways, for example, as 90003169 + 9903609 = 9487^2 + 3147^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

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, 342001 + ... + 342292.

Almost surely, 2^99906778 is an apocalyptic number.

99906778 is a deficient number, since it is larger than the sum of its proper divisors (52006490).

99906778 is a wasteful number, since it uses less digits than its factorization.

99906778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 684368.

The product of its (nonzero) digits is 1714608, while the sum is 55.

The square root of 99906778 is about 9995.3378132007. The cubic root of 99906778 is about 464.0146057878.

The spelling of 99906778 in words is "ninety-nine million, nine hundred six thousand, seven hundred seventy-eight".