164189781 has 64 divisors (see below), whose sum is σ = 288921600. Its totient is φ = 90211968.

The previous prime is 164189777. The next prime is 164189803. The reversal of 164189781 is 187981461.

It is a happy number.

164189781 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 164189781 - 2² = 164189777 is a prime.

It is a super-2 number, since 2×164189781² = 53916568369655922, which contains 22 as substring.

It is a hoax number, since the sum of its digits (45) coincides with the sum of the digits of its distinct prime factors.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (164189761) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 723190 + ... + 723416.

It is an arithmetic number, because the mean of its divisors is an integer number (4514400).

Almost surely, 2^164189781 is an apocalyptic number.

It is an amenable number.

164189781 is a deficient number, since it is larger than the sum of its proper divisors (124731819).

164189781 is a wasteful number, since it uses less digits than its factorization.

164189781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 375 (or 369 counting only the distinct ones).

The product of its digits is 96768, while the sum is 45.

The square root of 164189781 is about 12813.6560356520. The cubic root of 164189781 is about 547.5814253076.

The spelling of 164189781 in words is "one hundred sixty-four million, one hundred eighty-nine thousand, seven hundred eighty-one".