181451664 has 50 divisors (see below), whose sum is σ = 525177510. Its totient is φ = 60483456.

The previous prime is 181451657. The next prime is 181451689. The reversal of 181451664 is 466154181.

181451664 is a `hidden beast` number, since 1 + 81 + 4 + 516 + 64 = 666.

It can be written as a sum of positive squares in only one way, i.e., 156050064 + 25401600 = 12492^2 + 5040^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 68709 + ... + 71300.

Almost surely, 2^181451664 is an apocalyptic number.

It is an amenable number.

181451664 is an abundant number, since it is smaller than the sum of its proper divisors (343725846).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

181451664 is a wasteful number, since it uses less digits than its factorization.

181451664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 140029 (or 140014 counting only the distinct ones).

The product of its digits is 23040, while the sum is 36.

The square root of 181451664 is about 13470.3995486400. The cubic root of 181451664 is about 566.1354085911.

The spelling of 181451664 in words is "one hundred eighty-one million, four hundred fifty-one thousand, six hundred sixty-four".