1681764678 has 48 divisors (see below), whose sum is σ = 4208916816. Its totient is φ = 479646720.

The previous prime is 1681764673. The next prime is 1681764683. The reversal of 1681764678 is 8764671861.

1681764678 is a `hidden beast` number, since 1 + 6 + 8 + 176 + 467 + 8 = 666.

It is an interprime number because it is at equal distance from previous prime (1681764673) and next prime (1681764683).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1681764673) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 246451 + ... + 253182.

It is an arithmetic number, because the mean of its divisors is an integer number (87685767).

Almost surely, 2^1681764678 is an apocalyptic number.

1681764678 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

1681764678 is an abundant number, since it is smaller than the sum of its proper divisors (2527152138).

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

1681764678 is a wasteful number, since it uses less digits than its factorization.

1681764678 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 499669 (or 499666 counting only the distinct ones).

The product of its digits is 2709504, while the sum is 54.

The square root of 1681764678 is about 41009.3242811924. The cubic root of 1681764678 is about 1189.2004793561.

The spelling of 1681764678 in words is "one billion, six hundred eighty-one million, seven hundred sixty-four thousand, six hundred seventy-eight".