164421561 has 16 divisors (see below), whose sum is σ = 227952000. Its totient is φ = 105291648.

The previous prime is 164421559. The next prime is 164421601. The reversal of 164421561 is 165124461.

It is not a de Polignac number, because 164421561 - 2¹ = 164421559 is a prime.

It is a super-3 number, since 3×164421561³ (a number of 26 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (164421511) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12565 + ... + 22061.

It is an arithmetic number, because the mean of its divisors is an integer number (14247000).

Almost surely, 2^164421561 is an apocalyptic number.

It is an amenable number.

164421561 is a deficient number, since it is larger than the sum of its proper divisors (63530439).

164421561 is a wasteful number, since it uses less digits than its factorization.

164421561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9728.

The product of its digits is 5760, while the sum is 30.

The square root of 164421561 is about 12822.6971031839. The cubic root of 164421561 is about 547.8389702594.

The spelling of 164421561 in words is "one hundred sixty-four million, four hundred twenty-one thousand, five hundred sixty-one".