1629681 has 4 divisors (see below), whose sum is σ = 2172912. Its totient is φ = 1086452.

The previous prime is 1629673. The next prime is 1629689. The reversal of 1629681 is 1869261.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is an interprime number because it is at equal distance from previous prime (1629673) and next prime (1629689).

It is a cyclic number.

It is not a de Polignac number, because 1629681 - 2³ = 1629673 is a prime.

It is a super-2 number, since 2×1629681² = 5311720323522, which contains 22 as substring.

It is a D-number.

It is not an unprimeable number, because it can be changed into a prime (1629689) 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 3 ways as a sum of consecutive naturals, for example, 271611 + ... + 271616.

It is an arithmetic number, because the mean of its divisors is an integer number (543228).

2^1629681 is an apocalyptic number.

It is an amenable number.

1629681 is a deficient number, since it is larger than the sum of its proper divisors (543231).

1629681 is an equidigital number, since it uses as much as digits as its factorization.

1629681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 543230.

The product of its digits is 5184, while the sum is 33.

The square root of 1629681 is about 1276.5895973256. The cubic root of 1629681 is about 117.6795143446.

The spelling of 1629681 in words is "one million, six hundred twenty-nine thousand, six hundred eighty-one".