2185806640 has 40 divisors (see below), whose sum is σ = 5087085120. Its totient is φ = 873447936.

The previous prime is 2185806631. The next prime is 2185806653. The reversal of 2185806640 is 466085812.

It is a tau number, because it is divible by the number of its divisors (40).

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a junction number, because it is equal to n+sod(n) for n = 2185806593 and 2185806602.

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, 69972 + ... + 96268.

It is an arithmetic number, because the mean of its divisors is an integer number (127177128).

Almost surely, 2^2185806640 is an apocalyptic number.

2185806640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

2185806640 is an abundant number, since it is smaller than the sum of its proper divisors (2901278480).

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

2185806640 is a wasteful number, since it uses less digits than its factorization.

2185806640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27349 (or 27343 counting only the distinct ones).

The product of its (nonzero) digits is 92160, while the sum is 40.

The square root of 2185806640 is about 46752.6110500793. The cubic root of 2185806640 is about 1297.7884766385.

The spelling of 2185806640 in words is "two billion, one hundred eighty-five million, eight hundred six thousand, six hundred forty".