181981047 has 8 divisors (see below), whose sum is σ = 243183600. Its totient is φ = 121049600.

The previous prime is 181981013. The next prime is 181981081. The reversal of 181981047 is 740189181.

It is an interprime number because it is at equal distance from previous prime (181981013) and next prime (181981081).

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 181981047 - 2⁶ = 181980983 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 181980996 and 181981014.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (181981087) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 66204 + ... + 68897.

It is an arithmetic number, because the mean of its divisors is an integer number (30397950).

Almost surely, 2^181981047 is an apocalyptic number.

181981047 is a deficient number, since it is larger than the sum of its proper divisors (61202553).

181981047 is a wasteful number, since it uses less digits than its factorization.

181981047 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 135553.

The product of its (nonzero) digits is 16128, while the sum is 39.

The square root of 181981047 is about 13490.0351000285. The cubic root of 181981047 is about 566.6854384016.

The spelling of 181981047 in words is "one hundred eighty-one million, nine hundred eighty-one thousand, forty-seven".