1261051069 has 2 divisors, whose sum is σ = 1261051070. Its totient is φ = 1261051068.

The previous prime is 1261051049. The next prime is 1261051079. The reversal of 1261051069 is 9601501621.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 663835225 + 597215844 = 25765^2 + 24438^2 .

It is a cyclic number.

It is not a de Polignac number, because 1261051069 - 2⁵ = 1261051037 is a prime.

It is a super-2 number, since 2×1261051069² = 3180499597252085522, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 1261051069.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1261051039) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 630525534 + 630525535.

It is an arithmetic number, because the mean of its divisors is an integer number (630525535).

Almost surely, 2^1261051069 is an apocalyptic number.

It is an amenable number.

1261051069 is a deficient number, since it is larger than the sum of its proper divisors (1).

1261051069 is an equidigital number, since it uses as much as digits as its factorization.

1261051069 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3240, while the sum is 31.

The square root of 1261051069 is about 35511.2808696054. The cubic root of 1261051069 is about 1080.3825430970.

The spelling of 1261051069 in words is "one billion, two hundred sixty-one million, fifty-one thousand, sixty-nine".