1680635731 has 2 divisors, whose sum is σ = 1680635732. Its totient is φ = 1680635730.

The previous prime is 1680635713. The next prime is 1680635771. The reversal of 1680635731 is 1375360861.

It is a happy number.

Together with previous prime (1680635713) it forms an Ormiston pair, because they use the same digits, order apart.

It is an a-pointer prime, because the next prime (1680635771) can be obtained adding 1680635731 to its sum of digits (40).

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1680635731 - 2¹¹ = 1680633683 is a prime.

It is a super-2 number, since 2×1680635731² = 5649072920627808722, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1680635771) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 840317865 + 840317866.

It is an arithmetic number, because the mean of its divisors is an integer number (840317866).

Almost surely, 2^1680635731 is an apocalyptic number.

1680635731 is a deficient number, since it is larger than the sum of its proper divisors (1).

1680635731 is an equidigital number, since it uses as much as digits as its factorization.

1680635731 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 90720, while the sum is 40.

The square root of 1680635731 is about 40995.5574544365. The cubic root of 1680635731 is about 1188.9343214617.

The spelling of 1680635731 in words is "one billion, six hundred eighty million, six hundred thirty-five thousand, seven hundred thirty-one".