634981 has 4 divisors (see below), whose sum is σ = 649792. Its totient is φ = 620172.

The previous prime is 634979. The next prime is 635003. The reversal of 634981 is 189436.

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 a cyclic number.

It is not a de Polignac number, because 634981 - 2¹ = 634979 is a prime.

It is a super-2 number, since 2×634981² = 806401740722, which contains 22 as substring.

It is an Ulam number.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is a nialpdrome in base 15.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (634901) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7341 + ... + 7426.

It is an arithmetic number, because the mean of its divisors is an integer number (162448).

2⁶³⁴⁹⁸¹ is an apocalyptic number.

It is an amenable number.

634981 is a deficient number, since it is larger than the sum of its proper divisors (14811).

634981 is a wasteful number, since it uses less digits than its factorization.

634981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14810.

The product of its digits is 5184, while the sum is 31.

The square root of 634981 is about 796.8569507760. The cubic root of 634981 is about 85.9515230670.

The spelling of 634981 in words is "six hundred thirty-four thousand, nine hundred eighty-one".