66550378 has 4 divisors (see below), whose sum is σ = 99825570. Its totient is φ = 33275188.

The previous prime is 66550327. The next prime is 66550399. The reversal of 66550378 is 87305566.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 34774609 + 31775769 = 5897^2 + 5637^2 .

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a self number, because there is not a number n which added to its sum of digits gives 66550378.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 16637593 + ... + 16637596.

Almost surely, 2^66550378 is an apocalyptic number.

66550378 is a deficient number, since it is larger than the sum of its proper divisors (33275192).

66550378 is a wasteful number, since it uses less digits than its factorization.

66550378 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33275191.

The product of its (nonzero) digits is 151200, while the sum is 40.

The square root of 66550378 is about 8157.8415037312. The cubic root of 66550378 is about 405.2442321018.

The spelling of 66550378 in words is "sixty-six million, five hundred fifty thousand, three hundred seventy-eight".