678501091 has 4 divisors (see below), whose sum is σ = 682822912. Its totient is φ = 674179272.

The previous prime is 678501073. The next prime is 678501097. The reversal of 678501091 is 190105876.

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 678501091 - 2¹¹ = 678499043 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 678501091.

It is not an unprimeable number, because it can be changed into a prime (678501097) 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, 2160675 + ... + 2160988.

It is an arithmetic number, because the mean of its divisors is an integer number (170705728).

Almost surely, 2^678501091 is an apocalyptic number.

678501091 is a deficient number, since it is larger than the sum of its proper divisors (4321821).

678501091 is a wasteful number, since it uses less digits than its factorization.

678501091 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4321820.

The product of its (nonzero) digits is 15120, while the sum is 37.

The square root of 678501091 is about 26048.0534973345. The cubic root of 678501091 is about 878.7193367945.

The spelling of 678501091 in words is "six hundred seventy-eight million, five hundred one thousand, ninety-one".