1720956563 has 18 divisors (see below), whose sum is σ = 1847514948. Its totient is φ = 1602727360.

The previous prime is 1720956551. The next prime is 1720956569. The reversal of 1720956563 is 3656590271.

It is not a de Polignac number, because 1720956563 - 2⁴ = 1720956547 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1720956569) 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 17 ways as a sum of consecutive naturals, for example, 4959356 + ... + 4959702.

Almost surely, 2^1720956563 is an apocalyptic number.

1720956563 is a deficient number, since it is larger than the sum of its proper divisors (126558385).

1720956563 is an equidigital number, since it uses as much as digits as its factorization.

1720956563 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 643 (or 495 counting only the distinct ones).

The product of its (nonzero) digits is 340200, while the sum is 44.

The square root of 1720956563 is about 41484.4134947091. The cubic root of 1720956563 is about 1198.3673544998.

The spelling of 1720956563 in words is "one billion, seven hundred twenty million, nine hundred fifty-six thousand, five hundred sixty-three".