61780717 has 4 divisors (see below), whose sum is σ = 61839580. Its totient is φ = 61721856.

The previous prime is 61780711. The next prime is 61780753. The reversal of 61780717 is 71708716.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 37711881 + 24068836 = 6141^2 + 4906^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-61780717 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61780711) 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 in 3 ways as a sum of consecutive naturals, for example, 27828 + ... + 29965.

It is an arithmetic number, because the mean of its divisors is an integer number (15459895).

Almost surely, 2^61780717 is an apocalyptic number.

It is an amenable number.

61780717 is a deficient number, since it is larger than the sum of its proper divisors (58863).

61780717 is a wasteful number, since it uses less digits than its factorization.

61780717 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 58862.

The product of its (nonzero) digits is 16464, while the sum is 37.

The square root of 61780717 is about 7860.0710556585. The cubic root of 61780717 is about 395.3219977627.

The spelling of 61780717 in words is "sixty-one million, seven hundred eighty thousand, seven hundred seventeen".