66976649 has 4 divisors (see below), whose sum is σ = 67192320. Its totient is φ = 66760980.

The previous prime is 66976639. The next prime is 66976669. The reversal of 66976649 is 94667966.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 94667966 = 2 ⋅47333983.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66976649 is a prime.

It is a super-2 number, since 2×66976649² = 8971743022538402, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 66976649.

It is not an unprimeable number, because it can be changed into a prime (66976619) 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, 107369 + ... + 107990.

It is an arithmetic number, because the mean of its divisors is an integer number (16798080).

Almost surely, 2^66976649 is an apocalyptic number.

It is an amenable number.

66976649 is a deficient number, since it is larger than the sum of its proper divisors (215671).

66976649 is a wasteful number, since it uses less digits than its factorization.

66976649 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 215670.

The product of its digits is 2939328, while the sum is 53.

The square root of 66976649 is about 8183.9262582211. The cubic root of 66976649 is about 406.1076198804.

The spelling of 66976649 in words is "sixty-six million, nine hundred seventy-six thousand, six hundred forty-nine".