66377961 has 40 divisors (see below), whose sum is σ = 107704520. Its totient is φ = 40738464.

The previous prime is 66377923. The next prime is 66377981. The reversal of 66377961 is 16977366.

66377961 is a `hidden beast` number, since 6 + 637 + 7 + 9 + 6 + 1 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 18974736 + 47403225 = 4356^2 + 6885^2 .

It is not a de Polignac number, because 66377961 - 2⁹ = 66377449 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (66377981) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 177771 + ... + 178143.

It is an arithmetic number, because the mean of its divisors is an integer number (2692613).

Almost surely, 2^66377961 is an apocalyptic number.

It is an amenable number.

66377961 is a deficient number, since it is larger than the sum of its proper divisors (41326559).

66377961 is an equidigital number, since it uses as much as digits as its factorization.

66377961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 424 (or 389 counting only the distinct ones).

The product of its digits is 285768, while the sum is 45.

The square root of 66377961 is about 8147.2670878031. The cubic root of 66377961 is about 404.8939640099.

The spelling of 66377961 in words is "sixty-six million, three hundred seventy-seven thousand, nine hundred sixty-one".