61604561 has 2 divisors, whose sum is σ = 61604562. Its totient is φ = 61604560.

The previous prime is 61604531. The next prime is 61604579. The reversal of 61604561 is 16540616.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 52417600 + 9186961 = 7240^2 + 3031^2 .

It is a cyclic number.

It is not a de Polignac number, because 61604561 - 2²² = 57410257 is a prime.

It is a Chen prime.

It is equal to p_3651554 and since 61604561 and 3651554 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 (61604531) 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, 30802280 + 30802281.

It is an arithmetic number, because the mean of its divisors is an integer number (30802281).

Almost surely, 2^61604561 is an apocalyptic number.

It is an amenable number.

61604561 is a deficient number, since it is larger than the sum of its proper divisors (1).

61604561 is an equidigital number, since it uses as much as digits as its factorization.

61604561 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4320, while the sum is 29.

The square root of 61604561 is about 7848.8573053662. The cubic root of 61604561 is about 394.9459115171.

The spelling of 61604561 in words is "sixty-one million, six hundred four thousand, five hundred sixty-one".