1781980793 has 4 divisors (see below), whose sum is σ = 1782585168. Its totient is φ = 1781376420.

The previous prime is 1781980789. The next prime is 1781980799. The reversal of 1781980793 is 3970891871.

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: 3970891871 = 19 ⋅208994309.

It is a cyclic number.

It is not a de Polignac number, because 1781980793 - 2² = 1781980789 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1781980799) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 297743 + ... + 303668.

It is an arithmetic number, because the mean of its divisors is an integer number (445646292).

Almost surely, 2^1781980793 is an apocalyptic number.

It is an amenable number.

1781980793 is a deficient number, since it is larger than the sum of its proper divisors (604375).

1781980793 is an equidigital number, since it uses as much as digits as its factorization.

1781980793 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 604374.

The product of its (nonzero) digits is 762048, while the sum is 53.

The square root of 1781980793 is about 42213.5143407890. The cubic root of 1781980793 is about 1212.3676503855.

The spelling of 1781980793 in words is "one billion, seven hundred eighty-one million, nine hundred eighty thousand, seven hundred ninety-three".