61720018759 has 8 divisors (see below), whose sum is σ = 70576606880. Its totient is φ = 52873291296.

The previous prime is 61720018753. The next prime is 61720018793. The reversal of 61720018759 is 95781002716.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 61720018759 - 2⁷ = 61720018631 is a prime.

It is a super-2 number, since 2×61720018759² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61720018753) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2451744 + ... + 2476789.

It is an arithmetic number, because the mean of its divisors is an integer number (8822075860).

Almost surely, 2^61720018759 is an apocalyptic number.

61720018759 is a deficient number, since it is larger than the sum of its proper divisors (8856588121).

61720018759 is a wasteful number, since it uses less digits than its factorization.

61720018759 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4930329.

The product of its (nonzero) digits is 211680, while the sum is 46.

The spelling of 61720018759 in words is "sixty-one billion, seven hundred twenty million, eighteen thousand, seven hundred fifty-nine".