1597597409521 has 3 divisors (see below), whose sum is σ = 1597598673483. Its totient is φ = 1597596145560.

The previous prime is 1597597409509. The next prime is 1597597409537. The reversal of 1597597409521 is 1259047957951.

The square root of 1597597409521 is 1263961.

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

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in only one way, i.e., 1494479355121 + 103118054400 = 1222489^2 + 321120^2 .

It is not a de Polignac number, because 1597597409521 - 2¹¹ = 1597597407473 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1597597409561) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 631981 + ... + 1895941.

It is an arithmetic number, because the mean of its divisors is an integer number (532532891161).

Almost surely, 2^{1597597409521} is an apocalyptic number.

1597597409521 is the 1263961-st square number.

1597597409521 is the 631981-st centered octagonal number.

It is an amenable number.

1597597409521 is a deficient number, since it is larger than the sum of its proper divisors (1263962).

1597597409521 is an frugal number, since it uses more digits than its factorization.

1597597409521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2527922 (or 1263961 counting only the distinct ones).

The product of its (nonzero) digits is 35721000, while the sum is 64.

Multiplying 1597597409521 by its sum of digits (64), we get a square (102246234209344 = 10111688²).

The spelling of 1597597409521 in words is "one trillion, five hundred ninety-seven billion, five hundred ninety-seven million, four hundred nine thousand, five hundred twenty-one".