164198521 has 4 divisors (see below), whose sum is σ = 164230132. Its totient is φ = 164166912.

The previous prime is 164198509. The next prime is 164198533. The reversal of 164198521 is 125891461.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (164198509) and next prime (164198533).

It can be written as a sum of positive squares in 2 ways, for example, as 46172025 + 118026496 = 6795^2 + 10864^2 .

It is a cyclic number.

It is not a de Polignac number, because 164198521 - 2²⁵ = 130644089 is a prime.

It is a super-2 number, since 2×164198521² = 53922308597174882, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (164198591) 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, 5976 + ... + 19081.

It is an arithmetic number, because the mean of its divisors is an integer number (41057533).

Almost surely, 2^164198521 is an apocalyptic number.

It is an amenable number.

164198521 is a deficient number, since it is larger than the sum of its proper divisors (31611).

164198521 is an equidigital number, since it uses as much as digits as its factorization.

164198521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31610.

The product of its digits is 17280, while the sum is 37.

The square root of 164198521 is about 12813.9970735130. The cubic root of 164198521 is about 547.5911412528.

The spelling of 164198521 in words is "one hundred sixty-four million, one hundred ninety-eight thousand, five hundred twenty-one".