64542161 has 4 divisors (see below), whose sum is σ = 64558500. Its totient is φ = 64525824.

The previous prime is 64542143. The next prime is 64542187. The reversal of 64542161 is 16124546.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 16124546 = 2 ⋅8062273.

It can be written as a sum of positive squares in 2 ways, for example, as 29495761 + 35046400 = 5431^2 + 5920^2 .

It is a cyclic number.

It is not a de Polignac number, because 64542161 - 2¹⁸ = 64280017 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (64542461) 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, 1865 + ... + 11513.

It is an arithmetic number, because the mean of its divisors is an integer number (16139625).

Almost surely, 2^64542161 is an apocalyptic number.

It is an amenable number.

64542161 is a deficient number, since it is larger than the sum of its proper divisors (16339).

64542161 is an equidigital number, since it uses as much as digits as its factorization.

64542161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16338.

The product of its digits is 5760, while the sum is 29.

The square root of 64542161 is about 8033.8136025178. The cubic root of 64542161 is about 401.1263275720.

The spelling of 64542161 in words is "sixty-four million, five hundred forty-two thousand, one hundred sixty-one".