1781669349 has 24 divisors (see below), whose sum is σ = 2714119200. Its totient is φ = 1123126560.

The previous prime is 1781669339. The next prime is 1781669363. The reversal of 1781669349 is 9439661871.

It is not a de Polignac number, because 1781669349 - 2⁴ = 1781669333 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1781669295 and 1781669304.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1781669339) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 82882 + ... + 102140.

It is an arithmetic number, because the mean of its divisors is an integer number (113088300).

Almost surely, 2^1781669349 is an apocalyptic number.

1781669349 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

It is an amenable number.

1781669349 is a deficient number, since it is larger than the sum of its proper divisors (932449851).

1781669349 is a wasteful number, since it uses less digits than its factorization.

1781669349 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19825 (or 19822 counting only the distinct ones).

The product of its digits is 1959552, while the sum is 54.

The square root of 1781669349 is about 42209.8252661629. The cubic root of 1781669349 is about 1212.2970161356.

The spelling of 1781669349 in words is "one billion, seven hundred eighty-one million, six hundred sixty-nine thousand, three hundred forty-nine".