181738493 has 2 divisors, whose sum is σ = 181738494. Its totient is φ = 181738492.

The previous prime is 181738481. The next prime is 181738559. The reversal of 181738493 is 394837181.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 173106649 + 8631844 = 13157^2 + 2938^2 .

It is a cyclic number.

It is not a de Polignac number, because 181738493 - 2²⁶ = 114629629 is a prime.

It is a super-2 number, since 2×181738493² = 66057759675822098, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (181738423) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 90869246 + 90869247.

It is an arithmetic number, because the mean of its divisors is an integer number (90869247).

Almost surely, 2^181738493 is an apocalyptic number.

It is an amenable number.

181738493 is a deficient number, since it is larger than the sum of its proper divisors (1).

181738493 is an equidigital number, since it uses as much as digits as its factorization.

181738493 is an evil number, because the sum of its binary digits is even.

The product of its digits is 145152, while the sum is 44.

The square root of 181738493 is about 13481.0419849506. The cubic root of 181738493 is about 566.4335569831.

The spelling of 181738493 in words is "one hundred eighty-one million, seven hundred thirty-eight thousand, four hundred ninety-three".