1001785261 has 2 divisors, whose sum is σ = 1001785262. Its totient is φ = 1001785260.

The previous prime is 1001785223. The next prime is 1001785283. The reversal of 1001785261 is 1625871001.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1000773225 + 1012036 = 31635^2 + 1006^2 .

It is a cyclic number.

It is not a de Polignac number, because 1001785261 - 2⁷ = 1001785133 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1001785201) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 500892630 + 500892631.

It is an arithmetic number, because the mean of its divisors is an integer number (500892631).

Almost surely, 2^1001785261 is an apocalyptic number.

It is an amenable number.

1001785261 is a deficient number, since it is larger than the sum of its proper divisors (1).

1001785261 is an equidigital number, since it uses as much as digits as its factorization.

1001785261 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3360, while the sum is 31.

The square root of 1001785261 is about 31650.9914694627. The cubic root of 1001785261 is about 1000.5947332223.

The spelling of 1001785261 in words is "one billion, one million, seven hundred eighty-five thousand, two hundred sixty-one".