678535781 has 24 divisors (see below), whose sum is σ = 888871680. Its totient is φ = 511660800.

The previous prime is 678535717. The next prime is 678535783. The reversal of 678535781 is 187535876.

It is not a de Polignac number, because 678535781 - 2⁶ = 678535717 is a prime.

It is a super-2 number, since 2×678535781² = 920821612194559922, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (678535783) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3596 + ... + 37013.

It is an arithmetic number, because the mean of its divisors is an integer number (37036320).

Almost surely, 2^678535781 is an apocalyptic number.

It is an amenable number.

678535781 is a deficient number, since it is larger than the sum of its proper divisors (210335899).

678535781 is a wasteful number, since it uses less digits than its factorization.

678535781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40665 (or 40658 counting only the distinct ones).

The product of its digits is 1411200, while the sum is 50.

The square root of 678535781 is about 26048.7193735124. The cubic root of 678535781 is about 878.7343120858.

The spelling of 678535781 in words is "six hundred seventy-eight million, five hundred thirty-five thousand, seven hundred eighty-one".