61721105 has 8 divisors (see below), whose sum is σ = 75641472. Its totient is φ = 48326128.

The previous prime is 61721071. The next prime is 61721123. The reversal of 61721105 is 50112716.

61721105 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 61721105 - 2⁸ = 61720849 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 131087 + ... + 131556.

It is an arithmetic number, because the mean of its divisors is an integer number (9455184).

Almost surely, 2^61721105 is an apocalyptic number.

It is an amenable number.

61721105 is a deficient number, since it is larger than the sum of its proper divisors (13920367).

61721105 is a wasteful number, since it uses less digits than its factorization.

61721105 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 262695.

The product of its (nonzero) digits is 420, while the sum is 23.

The square root of 61721105 is about 7856.2780627979. The cubic root of 61721105 is about 395.1948085700.

The spelling of 61721105 in words is "sixty-one million, seven hundred twenty-one thousand, one hundred five".