1277019782809 has 3 divisors (see below), whose sum is σ = 1277020912863. Its totient is φ = 1277018652756.

The previous prime is 1277019782639. The next prime is 1277019782839. The reversal of 1277019782809 is 9082879107721.

The square root of 1277019782809 is 1130053.

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., 1267054153225 + 9965629584 = 1125635^2 + 99828^2 .

It is not a de Polignac number, because 1277019782809 - 2³⁷ = 1139580829337 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1277019782839) 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, 565027 + ... + 1695079.

It is an arithmetic number, because the mean of its divisors is an integer number (425673637621).

Almost surely, 2^{1277019782809} is an apocalyptic number.

1277019782809 is the 1130053-rd square number.

1277019782809 is the 565027-th centered octagonal number.

It is an amenable number.

1277019782809 is a deficient number, since it is larger than the sum of its proper divisors (1130054).

1277019782809 is an frugal number, since it uses more digits than its factorization.

1277019782809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2260106 (or 1130053 counting only the distinct ones).

The product of its (nonzero) digits is 7112448, while the sum is 61.

The spelling of 1277019782809 in words is "one trillion, two hundred seventy-seven billion, nineteen million, seven hundred eighty-two thousand, eight hundred nine".