1687170781920 has 192 divisors, whose sum is σ = 5724555971904. Its totient is φ = 415219875840.

The previous prime is 1687170781837. The next prime is 1687170782051. The reversal of 1687170781920 is 291870717861.

It is a congruent number.

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, 34426554 + ... + 34475526.

It is an arithmetic number, because the mean of its divisors is an integer number (29815395687).

Almost surely, 2^{1687170781920} is an apocalyptic number.

1687170781920 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 1687170781920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2862277985952).

1687170781920 is an abundant number, since it is smaller than the sum of its proper divisors (4037385189984).

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

1687170781920 is a wasteful number, since it uses less digits than its factorization.

1687170781920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 54525 (or 54517 counting only the distinct ones).

The product of its (nonzero) digits is 2370816, while the sum is 57.

The spelling of 1687170781920 in words is "one trillion, six hundred eighty-seven billion, one hundred seventy million, seven hundred eighty-one thousand, nine hundred twenty".