78990109 has 8 divisors (see below), whose sum is σ = 91240128. Its totient is φ = 67584960.

The previous prime is 78990103. The next prime is 78990133. The reversal of 78990109 is 90109987.

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

It is a cyclic number.

It is not a de Polignac number, because 78990109 - 2³ = 78990101 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78990101) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 211017 + ... + 211390.

It is an arithmetic number, because the mean of its divisors is an integer number (11405016).

Almost surely, 2^78990109 is an apocalyptic number.

It is an amenable number.

78990109 is a deficient number, since it is larger than the sum of its proper divisors (12250019).

78990109 is a wasteful number, since it uses less digits than its factorization.

78990109 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 422435.

The product of its (nonzero) digits is 40824, while the sum is 43.

The square root of 78990109 is about 8887.6379876770. The cubic root of 78990109 is about 429.0661344857.

The spelling of 78990109 in words is "seventy-eight million, nine hundred ninety thousand, one hundred nine".