61555189 has 2 divisors, whose sum is σ = 61555190. Its totient is φ = 61555188.

The previous prime is 61555187. The next prime is 61555237. The reversal of 61555189 is 98155516.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 60575089 + 980100 = 7783^2 + 990^2 .

It is a cyclic number.

It is not a de Polignac number, because 61555189 - 2¹ = 61555187 is a prime.

Together with 61555187, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (61555183) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30777594 + 30777595.

It is an arithmetic number, because the mean of its divisors is an integer number (30777595).

Almost surely, 2^61555189 is an apocalyptic number.

It is an amenable number.

61555189 is a deficient number, since it is larger than the sum of its proper divisors (1).

61555189 is an equidigital number, since it uses as much as digits as its factorization.

61555189 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 54000, while the sum is 40.

The square root of 61555189 is about 7845.7115037452. The cubic root of 61555189 is about 394.8403756029.

The spelling of 61555189 in words is "sixty-one million, five hundred fifty-five thousand, one hundred eighty-nine".