1618446989 has 2 divisors, whose sum is σ = 1618446990. Its totient is φ = 1618446988.

The previous prime is 1618446919. The next prime is 1618447001. The reversal of 1618446989 is 9896448161.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1517102500 + 101344489 = 38950^2 + 10067^2 .

It is a cyclic number.

It is not a de Polignac number, because 1618446989 - 2²⁰ = 1617398413 is a prime.

It is a super-4 number, since 4×1618446989⁴ (a number of 38 digits) contains 4444 as substring. Note that it is a super-d number also for d = 2.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1618446919) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 809223494 + 809223495.

It is an arithmetic number, because the mean of its divisors is an integer number (809223495).

Almost surely, 2^1618446989 is an apocalyptic number.

It is an amenable number.

1618446989 is a deficient number, since it is larger than the sum of its proper divisors (1).

1618446989 is an equidigital number, since it uses as much as digits as its factorization.

1618446989 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2985984, while the sum is 56.

The square root of 1618446989 is about 40229.9265348571. The cubic root of 1618446989 is about 1174.0848740572.

The spelling of 1618446989 in words is "one billion, six hundred eighteen million, four hundred forty-six thousand, nine hundred eighty-nine".