45131981 has 2 divisors, whose sum is σ = 45131982. Its totient is φ = 45131980.

The previous prime is 45131969. The next prime is 45131993. The reversal of 45131981 is 18913154.

It is a balanced prime because it is at equal distance from previous prime (45131969) and next prime (45131993).

It can be written as a sum of positive squares in only one way, i.e., 27984100 + 17147881 = 5290^2 + 4141^2 .

It is a cyclic number.

It is not a de Polignac number, because 45131981 - 2¹⁴ = 45115597 is a prime.

It is a super-2 number, since 2×45131981² = 4073791417968722, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (45131941) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 22565990 + 22565991.

It is an arithmetic number, because the mean of its divisors is an integer number (22565991).

Almost surely, 2^45131981 is an apocalyptic number.

It is an amenable number.

45131981 is a deficient number, since it is larger than the sum of its proper divisors (1).

45131981 is an equidigital number, since it uses as much as digits as its factorization.

45131981 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4320, while the sum is 32.

The square root of 45131981 is about 6718.0340130130. The cubic root of 45131981 is about 356.0367261063.

The spelling of 45131981 in words is "forty-five million, one hundred thirty-one thousand, nine hundred eighty-one".