1280713645 has 4 divisors (see below), whose sum is σ = 1536856380. Its totient is φ = 1024570912.

The previous prime is 1280713619. The next prime is 1280713667. The reversal of 1280713645 is 5463170821.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5463170821 = 67 ⋅81539863.

It can be written as a sum of positive squares in 2 ways, for example, as 693426889 + 587286756 = 26333^2 + 24234^2 .

It is a cyclic number.

It is not a de Polignac number, because 1280713645 - 2⁷ = 1280713517 is a prime.

It is a super-3 number, since 3×1280713645³ (a number of 28 digits) contains 333 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 128071360 + ... + 128071369.

It is an arithmetic number, because the mean of its divisors is an integer number (384214095).

Almost surely, 2^1280713645 is an apocalyptic number.

It is an amenable number.

1280713645 is a deficient number, since it is larger than the sum of its proper divisors (256142735).

1280713645 is an equidigital number, since it uses as much as digits as its factorization.

1280713645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 256142734.

The product of its (nonzero) digits is 40320, while the sum is 37.

The square root of 1280713645 is about 35787.0597423147. The cubic root of 1280713645 is about 1085.9687935823.

The spelling of 1280713645 in words is "one billion, two hundred eighty million, seven hundred thirteen thousand, six hundred forty-five".