1028105861 has 2 divisors, whose sum is σ = 1028105862. Its totient is φ = 1028105860.

The previous prime is 1028105851. The next prime is 1028105879. The reversal of 1028105861 is 1685018201.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 689325025 + 338780836 = 26255^2 + 18406^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1028105861 is a prime.

It is a super-2 number, since 2×1028105861² = 2114003322845102642, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1028105801) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 514052930 + 514052931.

It is an arithmetic number, because the mean of its divisors is an integer number (514052931).

Almost surely, 2^1028105861 is an apocalyptic number.

It is an amenable number.

1028105861 is a deficient number, since it is larger than the sum of its proper divisors (1).

1028105861 is an equidigital number, since it uses as much as digits as its factorization.

1028105861 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3840, while the sum is 32.

The square root of 1028105861 is about 32064.0898982023. The cubic root of 1028105861 is about 1009.2821946145.

The spelling of 1028105861 in words is "one billion, twenty-eight million, one hundred five thousand, eight hundred sixty-one".