66976669 has 2 divisors, whose sum is σ = 66976670. Its totient is φ = 66976668.

The previous prime is 66976639. The next prime is 66976681. The reversal of 66976669 is 96667966.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 45400644 + 21576025 = 6738^2 + 4645^2 .

It is a cyclic number.

It is not a de Polignac number, because 66976669 - 2⁷ = 66976541 is a prime.

It is a super-2 number, since 2×66976669² = 8971748380671122, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66976619) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33488334 + 33488335.

It is an arithmetic number, because the mean of its divisors is an integer number (33488335).

Almost surely, 2^66976669 is an apocalyptic number.

It is an amenable number.

66976669 is a deficient number, since it is larger than the sum of its proper divisors (1).

66976669 is an equidigital number, since it uses as much as digits as its factorization.

66976669 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4408992, while the sum is 55.

The square root of 66976669 is about 8183.9274801284. The cubic root of 66976669 is about 406.1076603032.

It can be divided in two parts, 6697 and 6669, that added together give a triangular number (13366 = T₁₆₃).

The spelling of 66976669 in words is "sixty-six million, nine hundred seventy-six thousand, six hundred sixty-nine".