1721360161 has 4 divisors (see below), whose sum is σ = 1722510000. Its totient is φ = 1720210324.

The previous prime is 1721360141. The next prime is 1721360167. The reversal of 1721360161 is 1610631271.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1610631271 = 5081 ⋅316991.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1721360161 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1721360167) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 572671 + ... + 575668.

It is an arithmetic number, because the mean of its divisors is an integer number (430627500).

Almost surely, 2^1721360161 is an apocalyptic number.

It is an amenable number.

1721360161 is a deficient number, since it is larger than the sum of its proper divisors (1149839).

1721360161 is a wasteful number, since it uses less digits than its factorization.

1721360161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1149838.

The product of its (nonzero) digits is 1512, while the sum is 28.

The square root of 1721360161 is about 41489.2776630300. The cubic root of 1721360161 is about 1198.4610273779.

The spelling of 1721360161 in words is "one billion, seven hundred twenty-one million, three hundred sixty thousand, one hundred sixty-one".