1720308641 has 4 divisors (see below), whose sum is σ = 1748510484. Its totient is φ = 1692106800.

The previous prime is 1720308631. The next prime is 1720308647. The reversal of 1720308641 is 1468030271.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1468030271 = 59 ⋅24881869.

It can be written as a sum of positive squares in 2 ways, for example, as 767290000 + 953018641 = 27700^2 + 30871^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1720308641 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1720308598 and 1720308607.

It is not an unprimeable number, because it can be changed into a prime (1720308647) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 14100830 + ... + 14100951.

It is an arithmetic number, because the mean of its divisors is an integer number (437127621).

Almost surely, 2^1720308641 is an apocalyptic number.

It is an amenable number.

1720308641 is a deficient number, since it is larger than the sum of its proper divisors (28201843).

1720308641 is an equidigital number, since it uses as much as digits as its factorization.

1720308641 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28201842.

The product of its (nonzero) digits is 8064, while the sum is 32.

The square root of 1720308641 is about 41476.6035374161. The cubic root of 1720308641 is about 1198.2169447312.

The spelling of 1720308641 in words is "one billion, seven hundred twenty million, three hundred eight thousand, six hundred forty-one".