66051561 has 16 divisors (see below), whose sum is σ = 92087424. Its totient is φ = 42033024.

The previous prime is 66051547. The next prime is 66051571. The reversal of 66051561 is 16515066.

It is not a de Polignac number, because 66051561 - 2⁵ = 66051529 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (66051571) 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, 58575 + ... + 59691.

It is an arithmetic number, because the mean of its divisors is an integer number (5755464).

Almost surely, 2^66051561 is an apocalyptic number.

It is an amenable number.

66051561 is a deficient number, since it is larger than the sum of its proper divisors (26035863).

66051561 is a wasteful number, since it uses less digits than its factorization.

66051561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2000.

The product of its (nonzero) digits is 5400, while the sum is 30.

The square root of 66051561 is about 8127.2111452822. The cubic root of 66051561 is about 404.2292122333.

The spelling of 66051561 in words is "sixty-six million, fifty-one thousand, five hundred sixty-one".