66377778 has 16 divisors (see below), whose sum is σ = 136344000. Its totient is φ = 21527856.

The previous prime is 66377777. The next prime is 66377797. The reversal of 66377778 is 87777366.

It is a self number, because there is not a number n which added to its sum of digits gives 66377778.

It is not an unprimeable number, because it can be changed into a prime (66377777) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 149278 + ... + 149721.

It is an arithmetic number, because the mean of its divisors is an integer number (8521500).

Almost surely, 2^66377778 is an apocalyptic number.

66377778 is an abundant number, since it is smaller than the sum of its proper divisors (69966222).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

66377778 is a wasteful number, since it uses less digits than its factorization.

66377778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 299041.

The product of its digits is 2074464, while the sum is 51.

The square root of 66377778 is about 8147.2558570355. The cubic root of 66377778 is about 404.8935919202.

The spelling of 66377778 in words is "sixty-six million, three hundred seventy-seven thousand, seven hundred seventy-eight".