1781798485 has 4 divisors (see below), whose sum is σ = 2138158188. Its totient is φ = 1425438784.

The previous prime is 1781798479. The next prime is 1781798489. The reversal of 1781798485 is 5848971871.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5848971871 = 10567 ⋅553513.

It can be written as a sum of positive squares in 2 ways, for example, as 839492676 + 942305809 = 28974^2 + 30697^2 .

It is a cyclic number.

It is not a de Polignac number, because 1781798485 - 2⁵ = 1781798453 is a prime.

It is a super-2 number, since 2×1781798485² = 6349611682296590450, which contains 22 as substring.

It is a Smith number, since the sum of its digits (58) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1781798489) 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, 178179844 + ... + 178179853.

It is an arithmetic number, because the mean of its divisors is an integer number (534539547).

Almost surely, 2^1781798485 is an apocalyptic number.

It is an amenable number.

1781798485 is a deficient number, since it is larger than the sum of its proper divisors (356359703).

1781798485 is an equidigital number, since it uses as much as digits as its factorization.

1781798485 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 356359702.

The product of its digits is 4515840, while the sum is 58.

The square root of 1781798485 is about 42211.3549296869. The cubic root of 1781798485 is about 1212.3263046613.

The spelling of 1781798485 in words is "one billion, seven hundred eighty-one million, seven hundred ninety-eight thousand, four hundred eighty-five".