678828091 has 4 divisors (see below), whose sum is σ = 678958912. Its totient is φ = 678697272.

The previous prime is 678828079. The next prime is 678828127. The reversal of 678828091 is 190828876.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 678828091 - 2⁹ = 678827579 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (678828041) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 57291 + ... + 68116.

It is an arithmetic number, because the mean of its divisors is an integer number (169739728).

Almost surely, 2^678828091 is an apocalyptic number.

678828091 is a deficient number, since it is larger than the sum of its proper divisors (130821).

678828091 is a wasteful number, since it uses less digits than its factorization.

678828091 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 130820.

The product of its (nonzero) digits is 387072, while the sum is 49.

The square root of 678828091 is about 26054.3296018147. The cubic root of 678828091 is about 878.8604788297.

The spelling of 678828091 in words is "six hundred seventy-eight million, eight hundred twenty-eight thousand, ninety-one".