633981 has 16 divisors (see below), whose sum is σ = 926208. Its totient is φ = 384000.

The previous prime is 633967. The next prime is 633991. The reversal of 633981 is 189336.

It is not a de Polignac number, because 633981 - 2⁹ = 633469 is a prime.

It is a super-2 number, since 2×633981² = 803863816722, which contains 22 as substring.

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 633981.

It is not an unprimeable number, because it can be changed into a prime (633931) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1381 + ... + 1781.

It is an arithmetic number, because the mean of its divisors is an integer number (57888).

2⁶³³⁹⁸¹ is an apocalyptic number.

It is an amenable number.

633981 is a deficient number, since it is larger than the sum of its proper divisors (292227).

633981 is a wasteful number, since it uses less digits than its factorization.

633981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 452.

The product of its digits is 3888, while the sum is 30.

The square root of 633981 is about 796.2292383479. The cubic root of 633981 is about 85.9063791006.

The spelling of 633981 in words is "six hundred thirty-three thousand, nine hundred eighty-one".