1278145563601 has 27 divisors (see below), whose sum is σ = 1378120144593. Its totient is φ = 1185179224320.

The previous prime is 1278145563547. The next prime is 1278145563613. The reversal of 1278145563601 is 1063655418721.

The square root of 1278145563601 is 1130551.

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

It can be written as a sum of positive squares in 4 ways, for example, as 161403866001 + 1116741697600 = 401751^2 + 1056760^2 .

It is not a de Polignac number, because 1278145563601 - 2¹³ = 1278145555409 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1278145563661) 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, 1403013336 + ... + 1403014246.

Almost surely, 2^{1278145563601} is an apocalyptic number.

1278145563601 is the 1130551-st square number.

1278145563601 is the 565276-th centered octagonal number.

It is an amenable number.

1278145563601 is a deficient number, since it is larger than the sum of its proper divisors (99974580992).

1278145563601 is an frugal number, since it uses more digits than its factorization.

1278145563601 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2002 (or 1001 counting only the distinct ones).

The product of its (nonzero) digits is 1209600, while the sum is 49.

Multiplying 1278145563601 by its sum of digits (49), we get a square (62629132616449 = 7913857²).

It can be divided in two parts, 12781455 and 63601, that added together give a square (12845056 = 3584²).

The spelling of 1278145563601 in words is "one trillion, two hundred seventy-eight billion, one hundred forty-five million, five hundred sixty-three thousand, six hundred one".