29981 has 4 divisors (see below), whose sum is σ = 34272. Its totient is φ = 25692.

The previous prime is 29959. The next prime is 29983. The reversal of 29981 is 18992.

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 29981 - 2⁶ = 29917 is a prime.

It is a super-2 number, since 2×29981² = 1797720722, 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 29981.

It is not an unprimeable number, because it can be changed into a prime (29983) 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, 2135 + ... + 2148.

It is an arithmetic number, because the mean of its divisors is an integer number (8568).

2²⁹⁹⁸¹ is an apocalyptic number.

It is an amenable number.

29981 is a deficient number, since it is larger than the sum of its proper divisors (4291).

29981 is an equidigital number, since it uses as much as digits as its factorization.

29981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4290.

The product of its digits is 1296, while the sum is 29.

The square root of 29981 is about 173.1502237943. The cubic root of 29981 is about 31.0657639612.

The spelling of 29981 in words is "twenty-nine thousand, nine hundred eighty-one".