1281681377 has 2 divisors, whose sum is σ = 1281681378. Its totient is φ = 1281681376.

The previous prime is 1281681343. The next prime is 1281681389. The reversal of 1281681377 is 7731861821.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1132255201 + 149426176 = 33649^2 + 12224^2 .

It is a cyclic number.

It is not a de Polignac number, because 1281681377 - 2¹⁰ = 1281680353 is a prime.

It is a super-2 number, since 2×1281681377² = 3285414304297232258, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1281681077) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 640840688 + 640840689.

It is an arithmetic number, because the mean of its divisors is an integer number (640840689).

Almost surely, 2^1281681377 is an apocalyptic number.

It is an amenable number.

1281681377 is a deficient number, since it is larger than the sum of its proper divisors (1).

1281681377 is an equidigital number, since it uses as much as digits as its factorization.

1281681377 is an evil number, because the sum of its binary digits is even.

The product of its digits is 112896, while the sum is 44.

The square root of 1281681377 is about 35800.5778863973. The cubic root of 1281681377 is about 1086.2422510585.

The spelling of 1281681377 in words is "one billion, two hundred eighty-one million, six hundred eighty-one thousand, three hundred seventy-seven".