61721565727 has 8 divisors (see below), whose sum is σ = 61778178000. Its totient is φ = 61664982720.

The previous prime is 61721565709. The next prime is 61721565739. The reversal of 61721565727 is 72756512716.

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

It is a cyclic number.

It is not a de Polignac number, because 61721565727 - 2¹⁵ = 61721532959 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 (61721565757) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6688977 + ... + 6698197.

It is an arithmetic number, because the mean of its divisors is an integer number (7722272250).

Almost surely, 2^61721565727 is an apocalyptic number.

61721565727 is a deficient number, since it is larger than the sum of its proper divisors (56612273).

61721565727 is a wasteful number, since it uses less digits than its factorization.

61721565727 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14633.

The product of its digits is 1234800, while the sum is 49.

The spelling of 61721565727 in words is "sixty-one billion, seven hundred twenty-one million, five hundred sixty-five thousand, seven hundred twenty-seven".