66763971 has 6 divisors (see below), whose sum is σ = 96436860. Its totient is φ = 44509308.

The previous prime is 66763969. The next prime is 66763979. The reversal of 66763971 is 17936766.

66763971 is a `hidden beast` number, since 6 + 6 + 7 + 639 + 7 + 1 = 666.

It is not a de Polignac number, because 66763971 - 2¹ = 66763969 is a prime.

It is not an unprimeable number, because it can be changed into a prime (66763979) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 3709101 + ... + 3709118.

It is an arithmetic number, because the mean of its divisors is an integer number (16072810).

Almost surely, 2^66763971 is an apocalyptic number.

66763971 is a deficient number, since it is larger than the sum of its proper divisors (29672889).

66763971 is a wasteful number, since it uses less digits than its factorization.

66763971 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7418225 (or 7418222 counting only the distinct ones).

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

The square root of 66763971 is about 8170.9222857643. The cubic root of 66763971 is about 405.6773120076.

The spelling of 66763971 in words is "sixty-six million, seven hundred sixty-three thousand, nine hundred seventy-one".