1617989 has 2 divisors, whose sum is σ = 1617990. Its totient is φ = 1617988.

The previous prime is 1617977. The next prime is 1618003. The reversal of 1617989 is 9897161.

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., 1481089 + 136900 = 1217^2 + 370^2 .

It is an emirp because it is prime and its reverse (9897161) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1617989 is a prime.

It is a Sophie Germain prime.

It is a Chen 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 (1617929) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 808994 + 808995.

It is an arithmetic number, because the mean of its divisors is an integer number (808995).

2^1617989 is an apocalyptic number.

It is an amenable number.

1617989 is a deficient number, since it is larger than the sum of its proper divisors (1).

1617989 is an equidigital number, since it uses as much as digits as its factorization.

1617989 is an evil number, because the sum of its binary digits is even.

The product of its digits is 27216, while the sum is 41.

The square root of 1617989 is about 1272.0019654073. The cubic root of 1617989 is about 117.3974115886.

The spelling of 1617989 in words is "one million, six hundred seventeen thousand, nine hundred eighty-nine".