61656559 has 2 divisors, whose sum is σ = 61656560. Its totient is φ = 61656558.

The previous prime is 61656547. The next prime is 61656563. The reversal of 61656559 is 95565616.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 61656559 - 2⁹ = 61656047 is a prime.

It is a plaindrome in base 16.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (61656589) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30828279 + 30828280.

It is an arithmetic number, because the mean of its divisors is an integer number (30828280).

Almost surely, 2^61656559 is an apocalyptic number.

61656559 is a deficient number, since it is larger than the sum of its proper divisors (1).

61656559 is an equidigital number, since it uses as much as digits as its factorization.

61656559 is an evil number, because the sum of its binary digits is even.

The product of its digits is 243000, while the sum is 43.

The square root of 61656559 is about 7852.1690633862. The cubic root of 61656559 is about 395.0569997325.

It can be divided in two parts, 616 and 56559, that added together give a palindrome (57175).

The spelling of 61656559 in words is "sixty-one million, six hundred fifty-six thousand, five hundred fifty-nine".