1678447749 has 12 divisors (see below), whose sum is σ = 2459874368. Its totient is φ = 1017240840.

The previous prime is 1678447741. The next prime is 1678447769. The reversal of 1678447749 is 9477448761.

It is not a de Polignac number, because 1678447749 - 2³ = 1678447741 is a prime.

It is a super-2 number, since 2×1678447749² = 5634373692246334002, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1678447741) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2311549 + ... + 2312274.

Almost surely, 2^1678447749 is an apocalyptic number.

It is an amenable number.

1678447749 is a deficient number, since it is larger than the sum of its proper divisors (781426619).

1678447749 is a wasteful number, since it uses less digits than its factorization.

1678447749 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4623848 (or 4623837 counting only the distinct ones).

The product of its digits is 9483264, while the sum is 57.

The square root of 1678447749 is about 40968.8631646034. The cubic root of 1678447749 is about 1188.4181484146.

The spelling of 1678447749 in words is "one billion, six hundred seventy-eight million, four hundred forty-seven thousand, seven hundred forty-nine".