1286113721 has 4 divisors (see below), whose sum is σ = 1330462500. Its totient is φ = 1241764944.

The previous prime is 1286113679. The next prime is 1286113753. The reversal of 1286113721 is 1273116821.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1273116821 = 1523 ⋅835927.

It can be written as a sum of positive squares in 2 ways, for example, as 685863721 + 600250000 = 26189^2 + 24500^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1286113721 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1286013721) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 22174346 + ... + 22174403.

It is an arithmetic number, because the mean of its divisors is an integer number (332615625).

Almost surely, 2^1286113721 is an apocalyptic number.

It is an amenable number.

1286113721 is a deficient number, since it is larger than the sum of its proper divisors (44348779).

1286113721 is an equidigital number, since it uses as much as digits as its factorization.

1286113721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44348778.

The product of its digits is 4032, while the sum is 32.

The square root of 1286113721 is about 35862.4277064451. The cubic root of 1286113721 is about 1087.4929675152.

The spelling of 1286113721 in words is "one billion, two hundred eighty-six million, one hundred thirteen thousand, seven hundred twenty-one".