181661457 has 8 divisors (see below), whose sum is σ = 250028800. Its totient is φ = 117200880.

The previous prime is 181661419. The next prime is 181661483. The reversal of 181661457 is 754166181.

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

It is not a de Polignac number, because 181661457 - 2⁶ = 181661393 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (181661657) 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, 976582 + ... + 976767.

It is an arithmetic number, because the mean of its divisors is an integer number (31253600).

Almost surely, 2^181661457 is an apocalyptic number.

It is an amenable number.

181661457 is a deficient number, since it is larger than the sum of its proper divisors (68367343).

181661457 is a wasteful number, since it uses less digits than its factorization.

181661457 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1953383.

The product of its digits is 40320, while the sum is 39.

The square root of 181661457 is about 13478.1844845662. The cubic root of 181661457 is about 566.3535116723.

The spelling of 181661457 in words is "one hundred eighty-one million, six hundred sixty-one thousand, four hundred fifty-seven".