1685217420 has 96 divisors (see below), whose sum is σ = 5249039040. Its totient is φ = 448865280.

The previous prime is 1685217419. The next prime is 1685217427. The reversal of 1685217420 is 247125861.

1685217420 is a `hidden beast` number, since 1 + 68 + 521 + 74 + 2 + 0 = 666.

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

It is not an unprimeable number, because it can be changed into a prime (1685217427) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 733794 + ... + 736086.

It is an arithmetic number, because the mean of its divisors is an integer number (54677490).

Almost surely, 2^1685217420 is an apocalyptic number.

1685217420 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 1685217420, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2624519520).

1685217420 is an abundant number, since it is smaller than the sum of its proper divisors (3563821620).

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

1685217420 is a wasteful number, since it uses less digits than its factorization.

1685217420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3672 (or 3664 counting only the distinct ones).

The product of its (nonzero) digits is 26880, while the sum is 36.

The square root of 1685217420 is about 41051.3997325304. The cubic root of 1685217420 is about 1190.0137512240.

The spelling of 1685217420 in words is "one billion, six hundred eighty-five million, two hundred seventeen thousand, four hundred twenty".