1864861 has 2 divisors, whose sum is σ = 1864862. Its totient is φ = 1864860.

The previous prime is 1864859. The next prime is 1864871. The reversal of 1864861 is 1684681.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 962361 + 902500 = 981^2 + 950^2 .

It is a cyclic number.

It is not a de Polignac number, because 1864861 - 2¹ = 1864859 is a prime.

Together with 1864859, it forms a pair of twin primes.

It is an Ulam number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1864801) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 932430 + 932431.

It is an arithmetic number, because the mean of its divisors is an integer number (932431).

2^1864861 is an apocalyptic number.

It is an amenable number.

1864861 is a deficient number, since it is larger than the sum of its proper divisors (1).

1864861 is an equidigital number, since it uses as much as digits as its factorization.

1864861 is an evil number, because the sum of its binary digits is even.

The product of its digits is 9216, while the sum is 34.

The square root of 1864861 is about 1365.5991359107. The cubic root of 1864861 is about 123.0879358835.

The spelling of 1864861 in words is "one million, eight hundred sixty-four thousand, eight hundred sixty-one".