678640731810 has 64 divisors (see below), whose sum is σ = 1682449367040. Its totient is φ = 175011042240.

The previous prime is 678640731803. The next prime is 678640731827. The reversal of 678640731810 is 18137046876.

It is a super-2 number, since 2×678640731810² (a number of 24 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1084719 + ... + 1591821.

It is an arithmetic number, because the mean of its divisors is an integer number (26288271360).

Almost surely, 2^678640731810 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 678640731810, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (841224683520).

678640731810 is an abundant number, since it is smaller than the sum of its proper divisors (1003808635230).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

678640731810 is a wasteful number, since it uses less digits than its factorization.

678640731810 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 508583.

The product of its (nonzero) digits is 1354752, while the sum is 51.

The spelling of 678640731810 in words is "six hundred seventy-eight billion, six hundred forty million, seven hundred thirty-one thousand, eight hundred ten".