1630681 has 6 divisors (see below), whose sum is σ = 1765950. Its totient is φ = 1505088.

The previous prime is 1630669. The next prime is 1630721. The reversal of 1630681 is 1860361.

It can be written as a sum of positive squares in 3 ways, for example, as 80656 + 1550025 = 284^2 + 1245^2 .

It is not a de Polignac number, because 1630681 - 2⁹ = 1630169 is a prime.

It is a super-3 number, since 3×1630681³ = 13008531944421333723, which contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1630621) 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 5 ways as a sum of consecutive naturals, for example, 4656 + ... + 4993.

It is an arithmetic number, because the mean of its divisors is an integer number (294325).

2^1630681 is an apocalyptic number.

It is an amenable number.

1630681 is a deficient number, since it is larger than the sum of its proper divisors (135269).

1630681 is an equidigital number, since it uses as much as digits as its factorization.

1630681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9675 (or 9662 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 25.

The square root of 1630681 is about 1276.9812058131. The cubic root of 1630681 is about 117.7035794740.

The spelling of 1630681 in words is "one million, six hundred thirty thousand, six hundred eighty-one".