45171981 has 12 divisors (see below), whose sum is σ = 65311740. Its totient is φ = 30085440.

The previous prime is 45171979. The next prime is 45171983. The reversal of 45171981 is 18917154.

It is an interprime number because it is at equal distance from previous prime (45171979) and next prime (45171983).

It can be written as a sum of positive squares in 2 ways, for example, as 34222500 + 10949481 = 5850^2 + 3309^2 .

It is not a de Polignac number, because 45171981 - 2¹ = 45171979 is a prime.

It is a super-2 number, since 2×45171981² = 4081015734928722, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (45171983) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 11635 + ... + 15023.

It is an arithmetic number, because the mean of its divisors is an integer number (5442645).

Almost surely, 2^45171981 is an apocalyptic number.

It is an amenable number.

45171981 is a deficient number, since it is larger than the sum of its proper divisors (20139759).

45171981 is a wasteful number, since it uses less digits than its factorization.

45171981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4876 (or 4873 counting only the distinct ones).

The product of its digits is 10080, while the sum is 36.

The square root of 45171981 is about 6721.0104151087. The cubic root of 45171981 is about 356.1418789155.

The spelling of 45171981 in words is "forty-five million, one hundred seventy-one thousand, nine hundred eighty-one".