1721791963 has 4 divisors (see below), whose sum is σ = 1722432600. Its totient is φ = 1721151328.

The previous prime is 1721791949. The next prime is 1721791993. The reversal of 1721791963 is 3691971271.

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 1721791963 - 2¹⁷ = 1721660891 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1721791993) 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, 316270 + ... + 321667.

It is an arithmetic number, because the mean of its divisors is an integer number (430608150).

Almost surely, 2^1721791963 is an apocalyptic number.

1721791963 is a deficient number, since it is larger than the sum of its proper divisors (640637).

1721791963 is an equidigital number, since it uses as much as digits as its factorization.

1721791963 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 640636.

The product of its digits is 142884, while the sum is 46.

The square root of 1721791963 is about 41494.4811149627. The cubic root of 1721791963 is about 1198.5612300384.

The spelling of 1721791963 in words is "one billion, seven hundred twenty-one million, seven hundred ninety-one thousand, nine hundred sixty-three".