61587720105 has 16 divisors (see below), whose sum is σ = 104336843904. Its totient is φ = 30914620160.

The previous prime is 61587720079. The next prime is 61587720143. The reversal of 61587720105 is 50102778516.

It is not a de Polignac number, because 61587720105 - 2⁹ = 61587719593 is a prime.

It is a super-2 number, since 2×61587720105² (a number of 22 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (42) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Curzon number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 120759981 + ... + 120760490.

It is an arithmetic number, because the mean of its divisors is an integer number (6521052744).

Almost surely, 2^61587720105 is an apocalyptic number.

It is an amenable number.

61587720105 is a deficient number, since it is larger than the sum of its proper divisors (42749123799).

61587720105 is a wasteful number, since it uses less digits than its factorization.

61587720105 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 241520496.

The product of its (nonzero) digits is 117600, while the sum is 42.

The spelling of 61587720105 in words is "sixty-one billion, five hundred eighty-seven million, seven hundred twenty thousand, one hundred five".