1305779287849 has 3 divisors (see below), whose sum is σ = 1305780430557. Its totient is φ = 1305778145142.

The previous prime is 1305779287807. The next prime is 1305779287859. The reversal of 1305779287849 is 9487829775031.

The square root of 1305779287849 is 1142707.

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 is not a de Polignac number, because 1305779287849 - 2³¹ = 1303631804201 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1305779287859) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 571354 + ... + 1714060.

It is an arithmetic number, because the mean of its divisors is an integer number (435260143519).

Almost surely, 2^{1305779287849} is an apocalyptic number.

1305779287849 is the 1142707-th square number.

1305779287849 is the 571354-th centered octagonal number.

It is an amenable number.

1305779287849 is a deficient number, since it is larger than the sum of its proper divisors (1142708).

1305779287849 is an frugal number, since it uses more digits than its factorization.

1305779287849 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2285414 (or 1142707 counting only the distinct ones).

The product of its (nonzero) digits is 213373440, while the sum is 70.

The spelling of 1305779287849 in words is "one trillion, three hundred five billion, seven hundred seventy-nine million, two hundred eighty-seven thousand, eight hundred forty-nine".