1005827861 has 2 divisors, whose sum is σ = 1005827862. Its totient is φ = 1005827860.

The previous prime is 1005827843. The next prime is 1005827863. The reversal of 1005827861 is 1687285001.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 671120836 + 334707025 = 25906^2 + 18295^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1005827861 is a prime.

Together with 1005827863, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1005827863) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 502913930 + 502913931.

It is an arithmetic number, because the mean of its divisors is an integer number (502913931).

Almost surely, 2^1005827861 is an apocalyptic number.

It is an amenable number.

1005827861 is a deficient number, since it is larger than the sum of its proper divisors (1).

1005827861 is an equidigital number, since it uses as much as digits as its factorization.

1005827861 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 26880, while the sum is 38.

The square root of 1005827861 is about 31714.7893103517. The cubic root of 1005827861 is about 1001.9388587307.

The spelling of 1005827861 in words is "one billion, five million, eight hundred twenty-seven thousand, eight hundred sixty-one".