1868561 has 2 divisors, whose sum is σ = 1868562. Its totient is φ = 1868560.

The previous prime is 1868549. The next prime is 1868567. The reversal of 1868561 is 1658681.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1809025 + 59536 = 1345^2 + 244^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1868561 is a prime.

It is an Ulam number.

It is not a weakly prime, because it can be changed into another prime (1868567) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 934280 + 934281.

It is an arithmetic number, because the mean of its divisors is an integer number (934281).

2^1868561 is an apocalyptic number.

It is an amenable number.

1868561 is a deficient number, since it is larger than the sum of its proper divisors (1).

1868561 is an equidigital number, since it uses as much as digits as its factorization.

1868561 is an evil number, because the sum of its binary digits is even.

The product of its digits is 11520, while the sum is 35.

The square root of 1868561 is about 1366.9531813489. The cubic root of 1868561 is about 123.1692868076.

The spelling of 1868561 in words is "one million, eight hundred sixty-eight thousand, five hundred sixty-one".