61744737604721 has 24 divisors (see below), whose sum is σ = 65743713822720. Its totient is φ = 57976946906112.

The previous prime is 61744737604717. The next prime is 61744737604727. The reversal of 61744737604721 is 12740673744716.

It is a happy number.

It is not a de Polignac number, because 61744737604721 - 2² = 61744737604717 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (61744737604727) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 578172896 + ... + 578279678.

It is an arithmetic number, because the mean of its divisors is an integer number (2739321409280).

Almost surely, 2^{61744737604721} is an apocalyptic number.

It is an amenable number.

61744737604721 is a deficient number, since it is larger than the sum of its proper divisors (3998976217999).

61744737604721 is a wasteful number, since it uses less digits than its factorization.

61744737604721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 111473 (or 111456 counting only the distinct ones).

The product of its (nonzero) digits is 33191424, while the sum is 59.

The spelling of 61744737604721 in words is "sixty-one trillion, seven hundred forty-four billion, seven hundred thirty-seven million, six hundred four thousand, seven hundred twenty-one".