1601721657743 has 4 divisors (see below), whose sum is σ = 1601878346208. Its totient is φ = 1601564969280.

The previous prime is 1601721657737. The next prime is 1601721657769. The reversal of 1601721657743 is 3477561271061.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1601721657743 - 2⁴ = 1601721657727 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1601721657691 and 1601721657700.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1601721657343) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 78328898 + ... + 78349343.

It is an arithmetic number, because the mean of its divisors is an integer number (400469586552).

Almost surely, 2^{1601721657743} is an apocalyptic number.

1601721657743 is a deficient number, since it is larger than the sum of its proper divisors (156688465).

1601721657743 is a wasteful number, since it uses less digits than its factorization.

1601721657743 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 156688464.

The product of its (nonzero) digits is 1481760, while the sum is 50.

The spelling of 1601721657743 in words is "one trillion, six hundred one billion, seven hundred twenty-one million, six hundred fifty-seven thousand, seven hundred forty-three".