45981 has 16 divisors (see below), whose sum is σ = 73920. Its totient is φ = 28080.

The previous prime is 45979. The next prime is 45989. The reversal of 45981 is 18954.

45981 = T₄₆ + T₄₇ + ... + T₇₁.

It is not a de Polignac number, because 45981 - 2¹ = 45979 is a prime.

It is a super-2 number, since 2×45981² = 4228504722, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

45981 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (45989) 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, 286 + ... + 416.

It is an arithmetic number, because the mean of its divisors is an integer number (4620).

2⁴⁵⁹⁸¹ is an apocalyptic number.

It is an amenable number.

45981 is a deficient number, since it is larger than the sum of its proper divisors (27939).

45981 is a wasteful number, since it uses less digits than its factorization.

45981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 153 (or 147 counting only the distinct ones).

The product of its digits is 1440, while the sum is 27.

The square root of 45981 is about 214.4318073421. The cubic root of 45981 is about 35.8255448489.

Subtracting from 45981 its sum of digits (27), we obtain a palindrome (45954).

The spelling of 45981 in words is "forty-five thousand, nine hundred eighty-one".