66777444 has 36 divisors (see below), whose sum is σ = 169285116. Its totient is φ = 22195008.

The previous prime is 66777427. The next prime is 66777461. The reversal of 66777444 is 44477766.

It is an interprime number because it is at equal distance from previous prime (66777427) and next prime (66777461).

It can be written as a sum of positive squares in 2 ways, for example, as 39841344 + 26936100 = 6312^2 + 5190^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is a zygodrome in base 10.

It is a self number, because there is not a number n which added to its sum of digits gives 66777444.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 10942 + ... + 15914.

Almost surely, 2^66777444 is an apocalyptic number.

It is an amenable number.

66777444 is an abundant number, since it is smaller than the sum of its proper divisors (102507672).

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

66777444 is a wasteful number, since it uses less digits than its factorization.

66777444 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5356 (or 5351 counting only the distinct ones).

The product of its digits is 790272, while the sum is 45.

The square root of 66777444 is about 8171.7466921093. The cubic root of 66777444 is about 405.7045987948.

The spelling of 66777444 in words is "sixty-six million, seven hundred seventy-seven thousand, four hundred forty-four".