61644595822721 has 8 divisors (see below), whose sum is σ = 61775662545984. Its totient is φ = 61513647127920.

The previous prime is 61644595822697. The next prime is 61644595822753. The reversal of 61644595822721 is 12722859544616.

It is a happy number.

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 61644595822721 - 2⁶ = 61644595822657 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (61644595842721) by changing a digit.

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, 28461395 + ... + 30550616.

It is an arithmetic number, because the mean of its divisors is an integer number (7721957818248).

Almost surely, 2^{61644595822721} is an apocalyptic number.

It is an amenable number.

61644595822721 is a deficient number, since it is larger than the sum of its proper divisors (131066723263).

61644595822721 is a wasteful number, since it uses less digits than its factorization.

61644595822721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 59014231.

The product of its digits is 58060800, while the sum is 62.

The spelling of 61644595822721 in words is "sixty-one trillion, six hundred forty-four billion, five hundred ninety-five million, eight hundred twenty-two thousand, seven hundred twenty-one".