66677840 has 40 divisors (see below), whose sum is σ = 163188960. Its totient is φ = 25266816.

The previous prime is 66677839. The next prime is 66677861. The reversal of 66677840 is 4877666.

It is a tau number, because it is divible by the number of its divisors (40).

It is a junction number, because it is equal to n+sod(n) for n = 66677791 and 66677800.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 20414 + ... + 23453.

It is an arithmetic number, because the mean of its divisors is an integer number (4079724).

Almost surely, 2^66677840 is an apocalyptic number.

It is an amenable number.

66677840 is an abundant number, since it is smaller than the sum of its proper divisors (96511120).

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

66677840 is a wasteful number, since it uses less digits than its factorization.

66677840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43899 (or 43893 counting only the distinct ones).

The product of its (nonzero) digits is 338688, while the sum is 44.

The square root of 66677840 is about 8165.6500047455. The cubic root of 66677840 is about 405.5027845962.

The spelling of 66677840 in words is "sixty-six million, six hundred seventy-seven thousand, eight hundred forty".