1609658256640 has 144 divisors (see below), whose sum is σ = 4414280024448. Its totient is φ = 550900850688.

The previous prime is 1609658256587. The next prime is 1609658256671. The reversal of 1609658256640 is 466528569061.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4884934 + ... + 5204026.

It is an arithmetic number, because the mean of its divisors is an integer number (30654722392).

Almost surely, 2^{1609658256640} is an apocalyptic number.

1609658256640 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 1609658256640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2207140012224).

1609658256640 is an abundant number, since it is smaller than the sum of its proper divisors (2804621767808).

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

1609658256640 is an equidigital number, since it uses as much as digits as its factorization.

1609658256640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 319684 (or 319670 counting only the distinct ones).

The product of its (nonzero) digits is 18662400, while the sum is 58.

The spelling of 1609658256640 in words is "one trillion, six hundred nine billion, six hundred fifty-eight million, two hundred fifty-six thousand, six hundred forty".