1686406940 has 24 divisors (see below), whose sum is σ = 3727847760. Its totient is φ = 639059328.

The previous prime is 1686406937. The next prime is 1686406961. The reversal of 1686406940 is 496046861.

It is a junction number, because it is equal to n+sod(n) for n = 1686406891 and 1686406900.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2218577 + ... + 2219336.

It is an arithmetic number, because the mean of its divisors is an integer number (155326990).

Almost surely, 2^1686406940 is an apocalyptic number.

1686406940 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1686406940 is an abundant number, since it is smaller than the sum of its proper divisors (2041440820).

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

1686406940 is a wasteful number, since it uses less digits than its factorization.

1686406940 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4437941 (or 4437939 counting only the distinct ones).

The product of its (nonzero) digits is 248832, while the sum is 44.

The square root of 1686406940 is about 41065.8853551217. The cubic root of 1686406940 is about 1190.2936779591.

The spelling of 1686406940 in words is "one billion, six hundred eighty-six million, four hundred six thousand, nine hundred forty".