678718081 has 8 divisors (see below), whose sum is σ = 725759784. Its totient is φ = 632467200.

The previous prime is 678718067. The next prime is 678718093. The reversal of 678718081 is 180817876.

It can be written as a sum of positive squares in 4 ways, for example, as 442050625 + 236667456 = 21025^2 + 15384^2 .

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 678718081 - 2⁷ = 678717953 is a prime.

It is a super-2 number, since 2×678718081² = 921316466952645122, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (678712081) 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, 195930 + ... + 199363.

It is an arithmetic number, because the mean of its divisors is an integer number (90719973).

Almost surely, 2^678718081 is an apocalyptic number.

It is an amenable number.

678718081 is a deficient number, since it is larger than the sum of its proper divisors (47041703).

678718081 is a wasteful number, since it uses less digits than its factorization.

678718081 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 395411.

The product of its (nonzero) digits is 150528, while the sum is 46.

The square root of 678718081 is about 26052.2183508430. The cubic root of 678718081 is about 878.8130006018.

The spelling of 678718081 in words is "six hundred seventy-eight million, seven hundred eighteen thousand, eighty-one".