1678945720 has 64 divisors (see below), whose sum is σ = 4077864000. Its totient is φ = 620218368.

The previous prime is 1678945717. The next prime is 1678945727. The reversal of 1678945720 is 275498761.

1678945720 = T₁₅₉ + T₁₆₀ + ... + T₂₁₅₉.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1678945727) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4785 + ... + 58144.

It is an arithmetic number, because the mean of its divisors is an integer number (63716625).

Almost surely, 2^1678945720 is an apocalyptic number.

1678945720 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1678945720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2038932000).

1678945720 is an abundant number, since it is smaller than the sum of its proper divisors (2398918280).

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

1678945720 is a wasteful number, since it uses less digits than its factorization.

1678945720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 62992 (or 62988 counting only the distinct ones).

The product of its (nonzero) digits is 846720, while the sum is 49.

The square root of 1678945720 is about 40974.9401463870. The cubic root of 1678945720 is about 1188.5356655785.

The spelling of 1678945720 in words is "one billion, six hundred seventy-eight million, nine hundred forty-five thousand, seven hundred twenty".