1858240561 has 2 divisors, whose sum is σ = 1858240562. Its totient is φ = 1858240560.

The previous prime is 1858240547. The next prime is 1858240583. The reversal of 1858240561 is 1650428581.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1158108961 + 700131600 = 34031^2 + 26460^2 .

It is an emirp because it is prime and its reverse (1650428581) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1858240561 is a prime.

It is not a weakly prime, because it can be changed into another prime (1858240061) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 929120280 + 929120281.

It is an arithmetic number, because the mean of its divisors is an integer number (929120281).

Almost surely, 2^1858240561 is an apocalyptic number.

It is an amenable number.

1858240561 is a deficient number, since it is larger than the sum of its proper divisors (1).

1858240561 is an equidigital number, since it uses as much as digits as its factorization.

1858240561 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 76800, while the sum is 40.

The square root of 1858240561 is about 43107.3144721403. The cubic root of 1858240561 is about 1229.4210510439.

The spelling of 1858240561 in words is "one billion, eight hundred fifty-eight million, two hundred forty thousand, five hundred sixty-one".