1681634 has 4 divisors (see below), whose sum is σ = 2522454. Its totient is φ = 840816.

The previous prime is 1681621. The next prime is 1681639. The reversal of 1681634 is 4361861.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 1315609 + 366025 = 1147^2 + 605^2 .

It is a plaindrome in base 15.

It is a junction number, because it is equal to n+sod(n) for n = 1681597 and 1681606.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1681639) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 420407 + ... + 420410.

2^1681634 is an apocalyptic number.

1681634 is a deficient number, since it is larger than the sum of its proper divisors (840820).

1681634 is an equidigital number, since it uses as much as digits as its factorization.

1681634 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 840819.

The product of its digits is 3456, while the sum is 29.

The square root of 1681634 is about 1296.7783156731. The cubic root of 1681634 is about 118.9169677115.

The spelling of 1681634 in words is "one million, six hundred eighty-one thousand, six hundred thirty-four".