78900091 has 8 divisors (see below), whose sum is σ = 80078544. Its totient is φ = 77729280.

The previous prime is 78900083. The next prime is 78900127. The reversal of 78900091 is 19000987.

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 78900091 - 2³ = 78900083 is a prime.

It is not an unprimeable number, because it can be changed into a prime (78900001) 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, 20856 + ... + 24346.

It is an arithmetic number, because the mean of its divisors is an integer number (10009818).

Almost surely, 2^78900091 is an apocalyptic number.

78900091 is a deficient number, since it is larger than the sum of its proper divisors (1178453).

78900091 is a wasteful number, since it uses less digits than its factorization.

78900091 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3821.

The product of its (nonzero) digits is 4536, while the sum is 34.

The square root of 78900091 is about 8882.5723188725. The cubic root of 78900091 is about 428.9030830309.

It can be divided in two parts, 7 and 8900091, that added together give a palindrome (8900098).

The spelling of 78900091 in words is "seventy-eight million, nine hundred thousand, ninety-one".