66977856 has 189 divisors, whose sum is σ = 218045919. Its totient is φ = 19641600.

The previous prime is 66977839. The next prime is 66977857. The reversal of 66977856 is 65877966.

It is a happy number.

The square root of 66977856 is 8184.

It is a perfect power (a square), and thus also a powerful number.

It is not an unprimeable number, because it can be changed into a prime (66977857) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 2160561 + ... + 2160591.

Almost surely, 2^66977856 is an apocalyptic number.

66977856 is a gapful number since it is divisible by the number (66) formed by its first and last digit.

66977856 is the 8184-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66977856

66977856 is an abundant number, since it is smaller than the sum of its proper divisors (151068063).

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

66977856 is a wasteful number, since it uses less digits than its factorization.

66977856 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 102 (or 47 counting only the distinct ones).

The product of its digits is 3810240, while the sum is 54.

The cubic root of 66977856 is about 406.1100593822.

The spelling of 66977856 in words is "sixty-six million, nine hundred seventy-seven thousand, eight hundred fifty-six".