629681 has 4 divisors (see below), whose sum is σ = 678132. Its totient is φ = 581232.

The previous prime is 629653. The next prime is 629683. The reversal of 629681 is 186926.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 186926 = 2 ⋅93463.

It can be written as a sum of positive squares in 2 ways, for example, as 167281 + 462400 = 409^2 + 680^2 .

It is a cyclic number.

It is not a de Polignac number, because 629681 - 2⁶ = 629617 is a prime.

It is a super-2 number, since 2×629681² = 792996323522, which contains 22 as substring.

It is an Ulam number.

It is not an unprimeable number, because it can be changed into a prime (629683) 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 3 ways as a sum of consecutive naturals, for example, 24206 + ... + 24231.

It is an arithmetic number, because the mean of its divisors is an integer number (169533).

2⁶²⁹⁶⁸¹ is an apocalyptic number.

It is an amenable number.

629681 is a deficient number, since it is larger than the sum of its proper divisors (48451).

629681 is a wasteful number, since it uses less digits than its factorization.

629681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 48450.

The product of its digits is 5184, while the sum is 32.

The square root of 629681 is about 793.5244167636. The cubic root of 629681 is about 85.7117172511.

The spelling of 629681 in words is "six hundred twenty-nine thousand, six hundred eighty-one".