1680778251 has 6 divisors (see below), whose sum is σ = 2427790820. Its totient is φ = 1120518828.

The previous prime is 1680778237. The next prime is 1680778277. The reversal of 1680778251 is 1528770861.

It is a happy number.

It is not a de Polignac number, because 1680778251 - 2⁷ = 1680778123 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1680778197 and 1680778206.

It is not an unprimeable number, because it can be changed into a prime (1680778651) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 93376561 + ... + 93376578.

Almost surely, 2^1680778251 is an apocalyptic number.

1680778251 is a deficient number, since it is larger than the sum of its proper divisors (747012569).

1680778251 is a wasteful number, since it uses less digits than its factorization.

1680778251 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 186753145 (or 186753142 counting only the distinct ones).

The product of its (nonzero) digits is 188160, while the sum is 45.

The square root of 1680778251 is about 40997.2956547136. The cubic root of 1680778251 is about 1188.9679282147.

The spelling of 1680778251 in words is "one billion, six hundred eighty million, seven hundred seventy-eight thousand, two hundred fifty-one".