60664537721 has 4 divisors (see below), whose sum is σ = 60799648500. Its totient is φ = 60529426944.

The previous prime is 60664537709. The next prime is 60664537727. The reversal of 60664537721 is 12773546606.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12773546606 = 2 ⋅6386773303.

It can be written as a sum of positive squares in 2 ways, for example, as 31298917225 + 29365620496 = 176915^2 + 171364^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-60664537721 is a prime.

It is a super-2 number, since 2×60664537721² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (60664537727) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 67554716 + ... + 67555613.

It is an arithmetic number, because the mean of its divisors is an integer number (15199912125).

Almost surely, 2^60664537721 is an apocalyptic number.

It is an amenable number.

60664537721 is a deficient number, since it is larger than the sum of its proper divisors (135110779).

60664537721 is a wasteful number, since it uses less digits than its factorization.

60664537721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 135110778.

The product of its (nonzero) digits is 1270080, while the sum is 47.

The spelling of 60664537721 in words is "sixty billion, six hundred sixty-four million, five hundred thirty-seven thousand, seven hundred twenty-one".