1243052861 has 4 divisors (see below), whose sum is σ = 1249362972. Its totient is φ = 1236742752.

The previous prime is 1243052857. The next prime is 1243052873. The reversal of 1243052861 is 1682503421.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1682503421 = 4229 ⋅397849.

It can be written as a sum of positive squares in 2 ways, for example, as 1196744836 + 46308025 = 34594^2 + 6805^2 .

It is a cyclic number.

It is not a de Polignac number, because 1243052861 - 2² = 1243052857 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1243052891) 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, 3154760 + ... + 3155153.

It is an arithmetic number, because the mean of its divisors is an integer number (312340743).

Almost surely, 2^1243052861 is an apocalyptic number.

It is an amenable number.

1243052861 is a deficient number, since it is larger than the sum of its proper divisors (6310111).

1243052861 is an equidigital number, since it uses as much as digits as its factorization.

1243052861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6310110.

The product of its (nonzero) digits is 11520, while the sum is 32.

The square root of 1243052861 is about 35256.9547890909. The cubic root of 1243052861 is about 1075.2180155624.

The spelling of 1243052861 in words is "one billion, two hundred forty-three million, fifty-two thousand, eight hundred sixty-one".