1681978914 has 192 divisors, whose sum is σ = 4992399360. Its totient is φ = 395746560.

The previous prime is 1681978913. The next prime is 1681978919. The reversal of 1681978914 is 4198791861.

1681978914 = T₄₁₂₄ + T₄₁₂₅ + ... + T₄₃₁₂.

It is not an unprimeable number, because it can be changed into a prime (1681978913) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 604294 + ... + 607070.

It is an arithmetic number, because the mean of its divisors is an integer number (26002080).

Almost surely, 2^1681978914 is an apocalyptic number.

1681978914 is a gapful number since it is divisible by the number (14) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 1681978914, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2496199680).

1681978914 is an abundant number, since it is smaller than the sum of its proper divisors (3310420446).

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

1681978914 is a wasteful number, since it uses less digits than its factorization.

1681978914 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2845 (or 2842 counting only the distinct ones).

The product of its digits is 870912, while the sum is 54.

The square root of 1681978914 is about 41011.9362381246. The cubic root of 1681978914 is about 1189.2509736850.

The spelling of 1681978914 in words is "one billion, six hundred eighty-one million, nine hundred seventy-eight thousand, nine hundred fourteen".