1618039861 has 2 divisors, whose sum is σ = 1618039862. Its totient is φ = 1618039860.

The previous prime is 1618039849. The next prime is 1618039873. The reversal of 1618039861 is 1689308161.

It is a happy number.

It is a balanced prime because it is at equal distance from previous prime (1618039849) and next prime (1618039873).

It can be written as a sum of positive squares in only one way, i.e., 1115159236 + 502880625 = 33394^2 + 22425^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1618039861 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1618039261) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 809019930 + 809019931.

It is an arithmetic number, because the mean of its divisors is an integer number (809019931).

Almost surely, 2^1618039861 is an apocalyptic number.

It is an amenable number.

1618039861 is a deficient number, since it is larger than the sum of its proper divisors (1).

1618039861 is an equidigital number, since it uses as much as digits as its factorization.

1618039861 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 62208, while the sum is 43.

The square root of 1618039861 is about 40224.8662023878. The cubic root of 1618039861 is about 1173.9864169320.

The spelling of 1618039861 in words is "one billion, six hundred eighteen million, thirty-nine thousand, eight hundred sixty-one".