66776951 has 4 divisors (see below), whose sum is σ = 67264512. Its totient is φ = 66289392.

The previous prime is 66776947. The next prime is 66776959. The reversal of 66776951 is 15967766.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 15967766 = 2 ⋅7983883.

It is a cyclic number.

It is not a de Polignac number, because 66776951 - 2² = 66776947 is a prime.

It is a super-2 number, since 2×66776951² = 8918322369712802, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 66776896 and 66776905.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66776959) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 243575 + ... + 243848.

It is an arithmetic number, because the mean of its divisors is an integer number (16816128).

Almost surely, 2^66776951 is an apocalyptic number.

66776951 is a deficient number, since it is larger than the sum of its proper divisors (487561).

66776951 is a wasteful number, since it uses less digits than its factorization.

66776951 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 487560.

The product of its digits is 476280, while the sum is 47.

The square root of 66776951 is about 8171.7165271441. The cubic root of 66776951 is about 405.7036003895.

The spelling of 66776951 in words is "sixty-six million, seven hundred seventy-six thousand, nine hundred fifty-one".