1955509 has 2 divisors, whose sum is σ = 1955510. Its totient is φ = 1955508.

The previous prime is 1955507. The next prime is 1955521. The reversal of 1955509 is 9055591.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1932100 + 23409 = 1390^2 + 153^2 .

It is an emirp because it is prime and its reverse (9055591) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1955509 - 2¹ = 1955507 is a prime.

Together with 1955507, it forms a pair of twin primes.

It is equal to p₁₄₅₈₈₈ and since 1955509 and 145888 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1955501) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 977754 + 977755.

It is an arithmetic number, because the mean of its divisors is an integer number (977755).

2^1955509 is an apocalyptic number.

It is an amenable number.

1955509 is a deficient number, since it is larger than the sum of its proper divisors (1).

1955509 is an equidigital number, since it uses as much as digits as its factorization.

1955509 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 10125, while the sum is 34.

The square root of 1955509 is about 1398.3951515934. The cubic root of 1955509 is about 125.0508379879.

The spelling of 1955509 in words is "one million, nine hundred fifty-five thousand, five hundred nine".