66677954241649 has 27 divisors (see below), whose sum is σ = 69596404717707. Its totient is φ = 63880653288816.

The previous prime is 66677954241643. The next prime is 66677954241653. The reversal of 66677954241649 is 94614245977666.

The square root of 66677954241649 is 8165657.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 48067944941025 + 18610009300624 = 6933105^2 + 4313932^2 .

It is not a de Polignac number, because 66677954241649 - 2⁵ = 66677954241617 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66677954241643) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 18609530512 + ... + 18609534094.

Almost surely, 2^{66677954241649} is an apocalyptic number.

66677954241649 is the 8165657-th square number.

66677954241649 is the 4082829-th centered octagonal number.

It is an amenable number.

66677954241649 is a deficient number, since it is larger than the sum of its proper divisors (2918450476058).

66677954241649 is an frugal number, since it uses more digits than its factorization.

66677954241649 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7358 (or 3679 counting only the distinct ones).

The product of its digits is 3292047360, while the sum is 76.

The spelling of 66677954241649 in words is "sixty-six trillion, six hundred seventy-seven billion, nine hundred fifty-four million, two hundred forty-one thousand, six hundred forty-nine".