61564609 has 2 divisors, whose sum is σ = 61564610. Its totient is φ = 61564608.

The previous prime is 61564603. The next prime is 61564619. The reversal of 61564609 is 90646516.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 50694400 + 10870209 = 7120^2 + 3297^2 .

It is a cyclic number.

It is not a de Polignac number, because 61564609 - 2⁵ = 61564577 is a prime.

It is equal to p_3649348 and since 61564609 and 3649348 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 (61564603) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30782304 + 30782305.

It is an arithmetic number, because the mean of its divisors is an integer number (30782305).

Almost surely, 2^61564609 is an apocalyptic number.

It is an amenable number.

61564609 is a deficient number, since it is larger than the sum of its proper divisors (1).

61564609 is an equidigital number, since it uses as much as digits as its factorization.

61564609 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 38880, while the sum is 37.

The square root of 61564609 is about 7846.3118087417. The cubic root of 61564609 is about 394.8605158309.

The spelling of 61564609 in words is "sixty-one million, five hundred sixty-four thousand, six hundred nine".