1261787143 has 2 divisors, whose sum is σ = 1261787144. Its totient is φ = 1261787142.

The previous prime is 1261787113. The next prime is 1261787147. The reversal of 1261787143 is 3417871621.

It is a happy number.

It is a strong prime.

It is an emirp because it is prime and its reverse (3417871621) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1261787143 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1261787096 and 1261787105.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1261787147) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 630893571 + 630893572.

It is an arithmetic number, because the mean of its divisors is an integer number (630893572).

Almost surely, 2^1261787143 is an apocalyptic number.

1261787143 is a deficient number, since it is larger than the sum of its proper divisors (1).

1261787143 is an equidigital number, since it uses as much as digits as its factorization.

1261787143 is an evil number, because the sum of its binary digits is even.

The product of its digits is 56448, while the sum is 40.

The square root of 1261787143 is about 35521.6433037662. The cubic root of 1261787143 is about 1080.5927082104.

The spelling of 1261787143 in words is "one billion, two hundred sixty-one million, seven hundred eighty-seven thousand, one hundred forty-three".