66776631 has 4 divisors (see below), whose sum is σ = 89035512. Its totient is φ = 44517752.

The previous prime is 66776623. The next prime is 66776669. The reversal of 66776631 is 13667766.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 66776631 - 2³ = 66776623 is a prime.

It is a super-2 number, since 2×66776631² = 8918236895420322, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66777631) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11129436 + ... + 11129441.

It is an arithmetic number, because the mean of its divisors is an integer number (22258878).

Almost surely, 2^66776631 is an apocalyptic number.

66776631 is a deficient number, since it is larger than the sum of its proper divisors (22258881).

66776631 is a wasteful number, since it uses less digits than its factorization.

66776631 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22258880.

The product of its digits is 190512, while the sum is 42.

The square root of 66776631 is about 8171.6969473910. The cubic root of 66776631 is about 405.7029523348.

The spelling of 66776631 in words is "sixty-six million, seven hundred seventy-six thousand, six hundred thirty-one".