258786881521 has 9 divisors (see below), whose sum is σ = 301041943371. Its totient is φ = 221814274752.

The previous prime is 258786881513. The next prime is 258786881531. The reversal of 258786881521 is 125188687852.

The square root of 258786881521 is 508711.

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

It can be written as a sum of positive squares in only one way, i.e., 119311522225 + 139475359296 = 345415^2 + 373464^2 .

It is not a de Polignac number, because 258786881521 - 2³ = 258786881513 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 258786881521.

It is not an unprimeable number, because it can be changed into a prime (258786881531) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 3524641 + ... + 3597313.

It is an arithmetic number, because the mean of its divisors is an integer number (33449104819).

Almost surely, 2^258786881521 is an apocalyptic number.

258786881521 is the 508711-st square number.

258786881521 is the 254356-th centered octagonal number.

It is an amenable number.

258786881521 is a deficient number, since it is larger than the sum of its proper divisors (42255061850).

258786881521 is an frugal number, since it uses more digits than its factorization.

258786881521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 145360 (or 72680 counting only the distinct ones).

The product of its digits is 17203200, while the sum is 61.

The spelling of 258786881521 in words is "two hundred fifty-eight billion, seven hundred eighty-six million, eight hundred eighty-one thousand, five hundred twenty-one".