1281560161 has 30 divisors (see below), whose sum is σ = 1564442530. Its totient is φ = 1049678784.

The previous prime is 1281560117. The next prime is 1281560201. The reversal of 1281560161 is 1610651821.

It can be written as a sum of positive squares in only one way, i.e., 995781136 + 285779025 = 31556^2 + 16905^2 .

It is not a de Polignac number, because 1281560161 - 2²⁵ = 1248005729 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1281560461) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 29 ways as a sum of consecutive naturals, for example, 1269625 + ... + 1270633.

Almost surely, 2^1281560161 is an apocalyptic number.

It is an amenable number.

1281560161 is a deficient number, since it is larger than the sum of its proper divisors (282882369).

1281560161 is an frugal number, since it uses more digits than its factorization.

1281560161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1083 (or 1039 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 31.

The square root of 1281560161 is about 35798.8849128014. The cubic root of 1281560161 is about 1086.2080059140.

The spelling of 1281560161 in words is "one billion, two hundred eighty-one million, five hundred sixty thousand, one hundred sixty-one".