66030320978 has 4 divisors (see below), whose sum is σ = 99045481470. Its totient is φ = 33015160488.

The previous prime is 66030320933. The next prime is 66030320981. The reversal of 66030320978 is 87902303066.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 87902303066 = 2 ⋅43951151533.

It can be written as a sum of positive squares in only one way, i.e., 54464824129 + 11565496849 = 233377^2 + 107543^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 16507580243 + ... + 16507580246.

Almost surely, 2^66030320978 is an apocalyptic number.

66030320978 is a deficient number, since it is larger than the sum of its proper divisors (33015160492).

66030320978 is a wasteful number, since it uses less digits than its factorization.

66030320978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33015160491.

The product of its (nonzero) digits is 326592, while the sum is 44.

The spelling of 66030320978 in words is "sixty-six billion, thirty million, three hundred twenty thousand, nine hundred seventy-eight".