1605361680 has 800 divisors, whose sum is σ = 6805814400. Its totient is φ = 346374144.

The previous prime is 1605361673. The next prime is 1605361717. The reversal of 1605361680 is 861635061.

It is a happy number.

1605361680 is a `hidden beast` number, since 1 + 60 + 536 + 1 + 68 + 0 = 666.

It is a super-2 number, since 2×1605361680² = 5154372247224844800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 159 ways as a sum of consecutive naturals, for example, 27209491 + ... + 27209549.

It is an arithmetic number, because the mean of its divisors is an integer number (8507268).

Almost surely, 2^1605361680 is an apocalyptic number.

1605361680 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 1605361680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3402907200).

1605361680 is an abundant number, since it is smaller than the sum of its proper divisors (5200452720).

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

1605361680 is a wasteful number, since it uses less digits than its factorization.

1605361680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 133 (or 118 counting only the distinct ones).

The product of its (nonzero) digits is 25920, while the sum is 36.

The square root of 1605361680 is about 40066.9649461998. The cubic root of 1605361680 is about 1170.9121092654.

The spelling of 1605361680 in words is "one billion, six hundred five million, three hundred sixty-one thousand, six hundred eighty".