164492581 has 4 divisors (see below), whose sum is σ = 179446464. Its totient is φ = 149538700.

The previous prime is 164492567. The next prime is 164492617. The reversal of 164492581 is 185294461.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 185294461 = 11 ⋅16844951.

It is a cyclic number.

It is not a de Polignac number, because 164492581 - 2⁷ = 164492453 is a prime.

It is a super-2 number, since 2×164492581² = 54115618408083122, which contains 22 as substring.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (164492551) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7476925 + ... + 7476946.

It is an arithmetic number, because the mean of its divisors is an integer number (44861616).

Almost surely, 2^164492581 is an apocalyptic number.

164492581 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

164492581 is the 6856-th centered heptagonal number.

It is an amenable number.

164492581 is a deficient number, since it is larger than the sum of its proper divisors (14953883).

164492581 is a wasteful number, since it uses less digits than its factorization.

164492581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14953882.

The product of its digits is 69120, while the sum is 40.

The square root of 164492581 is about 12825.4661123875. The cubic root of 164492581 is about 547.9178364837.

The spelling of 164492581 in words is "one hundred sixty-four million, four hundred ninety-two thousand, five hundred eighty-one".