1281377339 has 18 divisors (see below), whose sum is σ = 1436855148. Its totient is φ = 1133265000.

The previous prime is 1281377299. The next prime is 1281377341. The reversal of 1281377339 is 9337731821.

It is not a de Polignac number, because 1281377339 - 2¹⁶ = 1281311803 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1281377339.

It is not an unprimeable number, because it can be changed into a prime (1281377359) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 5104964 + ... + 5105214.

It is an arithmetic number, because the mean of its divisors is an integer number (79825286).

Almost surely, 2^1281377339 is an apocalyptic number.

1281377339 is a deficient number, since it is larger than the sum of its proper divisors (155477809).

1281377339 is an frugal number, since it uses more digits than its factorization.

1281377339 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 599 (or 305 counting only the distinct ones).

The product of its digits is 190512, while the sum is 44.

The square root of 1281377339 is about 35796.3313623058. The cubic root of 1281377339 is about 1086.1563521642.

Multiplying 1281377339 by its sum of digits (44), we get a square (56380602916 = 237446²).

The spelling of 1281377339 in words is "one billion, two hundred eighty-one million, three hundred seventy-seven thousand, three hundred thirty-nine".