61605289 has 2 divisors, whose sum is σ = 61605290. Its totient is φ = 61605288.

The previous prime is 61605241. The next prime is 61605307. The reversal of 61605289 is 98250616.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 58782889 + 2822400 = 7667^2 + 1680^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-61605289 is a prime.

It is equal to p_3651589 and since 61605289 and 3651589 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (61605589) by changing a digit.

It is a good prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30802644 + 30802645.

It is an arithmetic number, because the mean of its divisors is an integer number (30802645).

Almost surely, 2^61605289 is an apocalyptic number.

It is an amenable number.

61605289 is a deficient number, since it is larger than the sum of its proper divisors (1).

61605289 is an equidigital number, since it uses as much as digits as its factorization.

61605289 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 25920, while the sum is 37.

The square root of 61605289 is about 7848.9036814067. The cubic root of 61605289 is about 394.9474672433.

It can be divided in two parts, 6160 and 5289, that added together give a square (11449 = 107²).

The spelling of 61605289 in words is "sixty-one million, six hundred five thousand, two hundred eighty-nine".