1685355385220 has 48 divisors (see below), whose sum is σ = 3811646319600. Its totient is φ = 622260527616.

The previous prime is 1685355385213. The next prime is 1685355385243. The reversal of 1685355385220 is 225835535861.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 642575385664 + 1042779999556 = 801608^2 + 1021166^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7309214 + ... + 7536266.

It is an arithmetic number, because the mean of its divisors is an integer number (79409298325).

Almost surely, 2^{1685355385220} is an apocalyptic number.

1685355385220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1685355385220 is an abundant number, since it is smaller than the sum of its proper divisors (2126290934380).

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

1685355385220 is a wasteful number, since it uses less digits than its factorization.

1685355385220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 255624 (or 255622 counting only the distinct ones).

The product of its (nonzero) digits is 8640000, while the sum is 53.

The spelling of 1685355385220 in words is "one trillion, six hundred eighty-five billion, three hundred fifty-five million, three hundred eighty-five thousand, two hundred twenty".