1618520549 has 2 divisors, whose sum is σ = 1618520550. Its totient is φ = 1618520548.

The previous prime is 1618520507. The next prime is 1618520569. The reversal of 1618520549 is 9450258161.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 936788449 + 681732100 = 30607^2 + 26110^2 .

It is an emirp because it is prime and its reverse (9450258161) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1618520549 is a prime.

It is a super-2 number, since 2×1618520549² = 5239217535070522802, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1618520569) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 809260274 + 809260275.

It is an arithmetic number, because the mean of its divisors is an integer number (809260275).

Almost surely, 2^1618520549 is an apocalyptic number.

It is an amenable number.

1618520549 is a deficient number, since it is larger than the sum of its proper divisors (1).

1618520549 is an equidigital number, since it uses as much as digits as its factorization.

1618520549 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 86400, while the sum is 41.

The square root of 1618520549 is about 40230.8407692407. The cubic root of 1618520549 is about 1174.1026615567.

The spelling of 1618520549 in words is "one billion, six hundred eighteen million, five hundred twenty thousand, five hundred forty-nine".