164556561 has 16 divisors (see below), whose sum is σ = 236950784. Its totient is φ = 100980864.

The previous prime is 164556551. The next prime is 164556563. The reversal of 164556561 is 165655461.

It is not a de Polignac number, because 164556561 - 2⁷ = 164556433 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (164556563) 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, 8565 + ... + 20061.

It is an arithmetic number, because the mean of its divisors is an integer number (14809424).

Almost surely, 2^164556561 is an apocalyptic number.

It is an amenable number.

164556561 is a deficient number, since it is larger than the sum of its proper divisors (72394223).

164556561 is a wasteful number, since it uses less digits than its factorization.

164556561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11880.

The product of its digits is 108000, while the sum is 39.

The square root of 164556561 is about 12827.9601262243. The cubic root of 164556561 is about 547.9888655009.

The spelling of 164556561 in words is "one hundred sixty-four million, five hundred fifty-six thousand, five hundred sixty-one".