55578989 has 2 divisors, whose sum is σ = 55578990. Its totient is φ = 55578988.

The previous prime is 55578961. The next prime is 55578997. The reversal of 55578989 is 98987555.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 37002889 + 18576100 = 6083^2 + 4310^2 .

It is a cyclic number.

It is not a de Polignac number, because 55578989 - 2²⁴ = 38801773 is a prime.

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 (55578889) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27789494 + 27789495.

It is an arithmetic number, because the mean of its divisors is an integer number (27789495).

Almost surely, 2^55578989 is an apocalyptic number.

It is an amenable number.

55578989 is a deficient number, since it is larger than the sum of its proper divisors (1).

55578989 is an equidigital number, since it uses as much as digits as its factorization.

55578989 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4536000, while the sum is 56.

The square root of 55578989 is about 7455.1317225117. The cubic root of 55578989 is about 381.6250558383.

The spelling of 55578989 in words is "fifty-five million, five hundred seventy-eight thousand, nine hundred eighty-nine".