61660591 has 2 divisors, whose sum is σ = 61660592. Its totient is φ = 61660590.

The previous prime is 61660579. The next prime is 61660603. The reversal of 61660591 is 19506616.

It is a balanced prime because it is at equal distance from previous prime (61660579) and next prime (61660603).

It is a cyclic number.

It is not a de Polignac number, because 61660591 - 2⁵ = 61660559 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (61667591) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30830295 + 30830296.

It is an arithmetic number, because the mean of its divisors is an integer number (30830296).

Almost surely, 2^61660591 is an apocalyptic number.

61660591 is a deficient number, since it is larger than the sum of its proper divisors (1).

61660591 is an equidigital number, since it uses as much as digits as its factorization.

61660591 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 9720, while the sum is 34.

The square root of 61660591 is about 7852.4258035336. The cubic root of 61660591 is about 395.0656110634.

The spelling of 61660591 in words is "sixty-one million, six hundred sixty thousand, five hundred ninety-one".