1281646161 has 12 divisors (see below), whose sum is σ = 1851591040. Its totient is φ = 854281080.

The previous prime is 1281646147. The next prime is 1281646187. The reversal of 1281646161 is 1616461821.

1281646161 is a `hidden beast` number, since 1 + 2 + 8 + 1 + 646 + 1 + 6 + 1 = 666.

It is not a de Polignac number, because 1281646161 - 2⁵ = 1281646129 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1281641161) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 71496 + ... + 87606.

Almost surely, 2^1281646161 is an apocalyptic number.

It is an amenable number.

1281646161 is a deficient number, since it is larger than the sum of its proper divisors (569944879).

1281646161 is a wasteful number, since it uses less digits than its factorization.

1281646161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24956 (or 24953 counting only the distinct ones).

The product of its digits is 13824, while the sum is 36.

The square root of 1281646161 is about 35800.0860473826. The cubic root of 1281646161 is about 1086.2323022891.

The spelling of 1281646161 in words is "one billion, two hundred eighty-one million, six hundred forty-six thousand, one hundred sixty-one".