1609221639601 has 27 divisors (see below), whose sum is σ = 1680090947577. Its totient is φ = 1541289465000.

The previous prime is 1609221639581. The next prime is 1609221639617. The reversal of 1609221639601 is 1069361229061.

The square root of 1609221639601 is 1268551.

It is a perfect power (a square), and thus also a powerful number.

It is not a de Polignac number, because 1609221639601 - 2²⁷ = 1609087421873 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1609221639001) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 5938087096 + ... + 5938087366.

It is an arithmetic number, because the mean of its divisors is an integer number (62225590651).

Almost surely, 2^{1609221639601} is an apocalyptic number.

1609221639601 is the 1268551-st square number.

1609221639601 is the 634276-th centered octagonal number.

It is an amenable number.

1609221639601 is a deficient number, since it is larger than the sum of its proper divisors (70869307976).

1609221639601 is an frugal number, since it uses more digits than its factorization.

1609221639601 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 906 (or 453 counting only the distinct ones).

The product of its (nonzero) digits is 209952, while the sum is 46.

The spelling of 1609221639601 in words is "one trillion, six hundred nine billion, two hundred twenty-one million, six hundred thirty-nine thousand, six hundred one".