630981 has 12 divisors (see below), whose sum is σ = 981708. Its totient is φ = 388224.

The previous prime is 630967. The next prime is 630997. The reversal of 630981 is 189036.

It can be written as a sum of positive squares in 2 ways, for example, as 370881 + 260100 = 609^2 + 510^2 .

It is not a de Polignac number, because 630981 - 2¹⁹ = 106693 is a prime.

It is a super-2 number, since 2×630981² = 796274044722, which contains 22 as substring.

It is a hoax number, since the sum of its digits (27) coincides with the sum of the digits of its distinct prime factors.

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

It is a Curzon number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 630981.

It is not an unprimeable number, because it can be changed into a prime (630901) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2580 + ... + 2813.

It is an arithmetic number, because the mean of its divisors is an integer number (81809).

2⁶³⁰⁹⁸¹ is an apocalyptic number.

It is an amenable number.

630981 is a deficient number, since it is larger than the sum of its proper divisors (350727).

630981 is a wasteful number, since it uses less digits than its factorization.

630981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5412 (or 5409 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 27.

The square root of 630981 is about 794.3431248522. The cubic root of 630981 is about 85.7706617218.

The spelling of 630981 in words is "six hundred thirty thousand, nine hundred eighty-one".