1609640 has 16 divisors (see below), whose sum is σ = 3621780. Its totient is φ = 643840.

The previous prime is 1609631. The next prime is 1609667. The reversal of 1609640 is 469061.

It can be written as a sum of positive squares in 2 ways, for example, as 1444804 + 164836 = 1202^2 + 406^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 20081 + ... + 20160.

2^1609640 is an apocalyptic number.

1609640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1609640 is an abundant number, since it is smaller than the sum of its proper divisors (2012140).

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

1609640 is a wasteful number, since it uses less digits than its factorization.

1609640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40252 (or 40248 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 26.

The square root of 1609640 is about 1268.7158862409. The cubic root of 1609640 is about 117.1951354432.

The spelling of 1609640 in words is "one million, six hundred nine thousand, six hundred forty".