66784077 has 12 divisors (see below), whose sum is σ = 96540444. Its totient is φ = 44488320.

The previous prime is 66784057. The next prime is 66784097. The reversal of 66784077 is 77048766.

It is an interprime number because it is at equal distance from previous prime (66784057) and next prime (66784097).

It can be written as a sum of positive squares in 2 ways, for example, as 21706281 + 45077796 = 4659^2 + 6714^2 .

It is not a de Polignac number, because 66784077 - 2¹² = 66779981 is a prime.

It is a super-2 number, since 2×66784077² = 8920225881483858, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66784027) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 15877 + ... + 19637.

It is an arithmetic number, because the mean of its divisors is an integer number (8045037).

Almost surely, 2^66784077 is an apocalyptic number.

It is an amenable number.

66784077 is a deficient number, since it is larger than the sum of its proper divisors (29756367).

66784077 is a wasteful number, since it uses less digits than its factorization.

66784077 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5740 (or 5737 counting only the distinct ones).

The product of its (nonzero) digits is 395136, while the sum is 45.

The square root of 66784077 is about 8172.1525316161. The cubic root of 66784077 is about 405.7180312222.

The spelling of 66784077 in words is "sixty-six million, seven hundred eighty-four thousand, seventy-seven".