66043511961 has 32 divisors (see below), whose sum is σ = 103188569088. Its totient is φ = 36786173760.

The previous prime is 66043511951. The next prime is 66043511983. The reversal of 66043511961 is 16911534066.

It is not a de Polignac number, because 66043511961 - 2¹⁴ = 66043495577 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (66043511951) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 368895 + ... + 517851.

It is an arithmetic number, because the mean of its divisors is an integer number (3224642784).

Almost surely, 2^66043511961 is an apocalyptic number.

It is an amenable number.

66043511961 is a deficient number, since it is larger than the sum of its proper divisors (37145057127).

66043511961 is a wasteful number, since it uses less digits than its factorization.

66043511961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 149501.

The product of its (nonzero) digits is 116640, while the sum is 42.

The spelling of 66043511961 in words is "sixty-six billion, forty-three million, five hundred eleven thousand, nine hundred sixty-one".