145981 has 8 divisors (see below), whose sum is σ = 166464. Its totient is φ = 126720.

The previous prime is 145969. The next prime is 145987. The reversal of 145981 is 189541.

It is a happy number.

145981 is nontrivially palindromic in base 14.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 145981 - 2⁵ = 145949 is a prime.

It is a super-3 number, since 3×145981³ = 9332763438333423, which contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (145987) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 36 + ... + 541.

It is an arithmetic number, because the mean of its divisors is an integer number (20808).

2¹⁴⁵⁹⁸¹ is an apocalyptic number.

145981 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

145981 is a deficient number, since it is larger than the sum of its proper divisors (20483).

145981 is a wasteful number, since it uses less digits than its factorization.

145981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 611.

The product of its digits is 1440, while the sum is 28.

The square root of 145981 is about 382.0746000456. The cubic root of 145981 is about 52.6540900020.

It can be divided in two parts, 1459 and 81, that added together give a triangular number (1540 = T₅₅).

The spelling of 145981 in words is "one hundred forty-five thousand, nine hundred eighty-one".