1640705984 has 28 divisors (see below), whose sum is σ = 3310966200. Its totient is φ = 806446848.

The previous prime is 1640705981. The next prime is 1640706037. The reversal of 1640705984 is 4895070461.

It is a super-2 number, since 2×1640705984² = 5383832251866816512, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1640705981) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 213479 + ... + 221030.

Almost surely, 2^1640705984 is an apocalyptic number.

It is an amenable number.

1640705984 is an abundant number, since it is smaller than the sum of its proper divisors (1670260216).

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

1640705984 is an equidigital number, since it uses as much as digits as its factorization.

1640705984 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 434580 (or 434570 counting only the distinct ones).

The product of its (nonzero) digits is 241920, while the sum is 44.

The square root of 1640705984 is about 40505.6290409123. The cubic root of 1640705984 is about 1179.4429008667.

The spelling of 1640705984 in words is "one billion, six hundred forty million, seven hundred five thousand, nine hundred eighty-four".