55571389 has 2 divisors, whose sum is σ = 55571390. Its totient is φ = 55571388.

The previous prime is 55571387. The next prime is 55571407. The reversal of 55571389 is 98317555.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 47403225 + 8168164 = 6885^2 + 2858^2 .

It is a cyclic number.

It is not a de Polignac number, because 55571389 - 2¹ = 55571387 is a prime.

Together with 55571387, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (55571387) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27785694 + 27785695.

It is an arithmetic number, because the mean of its divisors is an integer number (27785695).

Almost surely, 2^55571389 is an apocalyptic number.

It is an amenable number.

55571389 is a deficient number, since it is larger than the sum of its proper divisors (1).

55571389 is an equidigital number, since it uses as much as digits as its factorization.

55571389 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 189000, while the sum is 43.

The square root of 55571389 is about 7454.6219890750. The cubic root of 55571389 is about 381.6076602800.

The spelling of 55571389 in words is "fifty-five million, five hundred seventy-one thousand, three hundred eighty-nine".