61564823 has 2 divisors, whose sum is σ = 61564824. Its totient is φ = 61564822.

The previous prime is 61564817. The next prime is 61564831. The reversal of 61564823 is 32846516.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 61564823 - 2¹⁶ = 61499287 is a prime.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (61564843) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30782411 + 30782412.

It is an arithmetic number, because the mean of its divisors is an integer number (30782412).

Almost surely, 2^61564823 is an apocalyptic number.

61564823 is a deficient number, since it is larger than the sum of its proper divisors (1).

61564823 is an equidigital number, since it uses as much as digits as its factorization.

61564823 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 34560, while the sum is 35.

The square root of 61564823 is about 7846.3254457102. The cubic root of 61564823 is about 394.8609733451.

The spelling of 61564823 in words is "sixty-one million, five hundred sixty-four thousand, eight hundred twenty-three".