66881856 has 56 divisors (see below), whose sum is σ = 181095904. Its totient is φ = 21772800.

The previous prime is 66881839. The next prime is 66881873. The reversal of 66881856 is 65818866.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (66881839) and next prime (66881873).

It is a Harshad number since it is a multiple of its sum of digits (48).

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, 4206 + ... + 12306.

Almost surely, 2^66881856 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66881856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (90547952).

66881856 is an abundant number, since it is smaller than the sum of its proper divisors (114214048).

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

66881856 is a wasteful number, since it uses less digits than its factorization.

66881856 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8159 (or 8149 counting only the distinct ones).

The product of its digits is 552960, while the sum is 48.

The square root of 66881856 is about 8178.1327942263. The cubic root of 66881856 is about 405.9159394671.

The spelling of 66881856 in words is "sixty-six million, eight hundred eighty-one thousand, eight hundred fifty-six".