181975481 has 2 divisors, whose sum is σ = 181975482. Its totient is φ = 181975480.

The previous prime is 181975457. The next prime is 181975499. The reversal of 181975481 is 184579181.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 118613881 + 63361600 = 10891^2 + 7960^2 .

It is a cyclic number.

It is not a de Polignac number, because 181975481 - 2²⁶ = 114866617 is a prime.

It is a super-2 number, since 2×181975481² = 66230151370362722, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (181975181) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 90987740 + 90987741.

It is an arithmetic number, because the mean of its divisors is an integer number (90987741).

Almost surely, 2^181975481 is an apocalyptic number.

It is an amenable number.

181975481 is a deficient number, since it is larger than the sum of its proper divisors (1).

181975481 is an equidigital number, since it uses as much as digits as its factorization.

181975481 is an evil number, because the sum of its binary digits is even.

The product of its digits is 80640, while the sum is 44.

The square root of 181975481 is about 13489.8287980241. The cubic root of 181975481 is about 566.6796608708.

The spelling of 181975481 in words is "one hundred eighty-one million, nine hundred seventy-five thousand, four hundred eighty-one".