1781087616 has 640 divisors, whose sum is σ = 6966812160. Its totient is φ = 437944320.

The previous prime is 1781087597. The next prime is 1781087617. The reversal of 1781087616 is 6167801871.

It is a happy number.

1781087616 is a `hidden beast` number, since 17 + 8 + 10 + 8 + 7 + 616 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1781087617) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 18361680 + ... + 18361776.

It is an arithmetic number, because the mean of its divisors is an integer number (10885644).

Almost surely, 2^1781087616 is an apocalyptic number.

1781087616 is a gapful number since it is divisible by the number (16) 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 1781087616, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3483406080).

1781087616 is an abundant number, since it is smaller than the sum of its proper divisors (5185724544).

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

1781087616 is a wasteful number, since it uses less digits than its factorization.

1781087616 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 164 (or 143 counting only the distinct ones).

The product of its (nonzero) digits is 112896, while the sum is 45.

The square root of 1781087616 is about 42202.9337368861. The cubic root of 1781087616 is about 1212.1650593747.

The spelling of 1781087616 in words is "one billion, seven hundred eighty-one million, eighty-seven thousand, six hundred sixteen".