1261789 has 2 divisors, whose sum is σ = 1261790. Its totient is φ = 1261788.

The previous prime is 1261769. The next prime is 1261801. The reversal of 1261789 is 9871621.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 736164 + 525625 = 858^2 + 725^2 .

It is a cyclic number.

It is not a de Polignac number, because 1261789 - 2¹⁵ = 1229021 is a prime.

It is a super-2 number, since 2×1261789² = 3184222961042, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1261739) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 630894 + 630895.

It is an arithmetic number, because the mean of its divisors is an integer number (630895).

2^1261789 is an apocalyptic number.

It is an amenable number.

1261789 is a deficient number, since it is larger than the sum of its proper divisors (1).

1261789 is an equidigital number, since it uses as much as digits as its factorization.

1261789 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6048, while the sum is 34.

The square root of 1261789 is about 1123.2938173069. The cubic root of 1261789 is about 108.0593238321.

The spelling of 1261789 in words is "one million, two hundred sixty-one thousand, seven hundred eighty-nine".