1684256640 has 256 divisors, whose sum is σ = 6202448640. Its totient is φ = 384204800.

The previous prime is 1684256633. The next prime is 1684256647. The reversal of 1684256640 is 466524861.

It is an interprime number because it is at equal distance from previous prime (1684256633) and next prime (1684256647).

It is a super-3 number, since 3×1684256640³ (a number of 29 digits) contains 333 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1684256592 and 1684256601.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1684256647) 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, 356695 + ... + 361385.

It is an arithmetic number, because the mean of its divisors is an integer number (24228315).

Almost surely, 2^1684256640 is an apocalyptic number.

1684256640 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 1684256640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3101224320).

1684256640 is an abundant number, since it is smaller than the sum of its proper divisors (4518192000).

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

1684256640 is a wasteful number, since it uses less digits than its factorization.

1684256640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4741 (or 4729 counting only the distinct ones).

The product of its (nonzero) digits is 276480, while the sum is 42.

The square root of 1684256640 is about 41039.6959053061. The cubic root of 1684256640 is about 1189.7875571142.

The spelling of 1684256640 in words is "one billion, six hundred eighty-four million, two hundred fifty-six thousand, six hundred forty".