66918984 has 32 divisors (see below), whose sum is σ = 182507040. Its totient is φ = 20278400.

The previous prime is 66918959. The next prime is 66918989. The reversal of 66918984 is 48981966.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (66918989) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 126477 + ... + 127004.

It is an arithmetic number, because the mean of its divisors is an integer number (5703345).

Almost surely, 2^66918984 is an apocalyptic number.

It is an amenable number.

66918984 is an abundant number, since it is smaller than the sum of its proper divisors (115588056).

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

66918984 is a wasteful number, since it uses less digits than its factorization.

66918984 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 253501 (or 253497 counting only the distinct ones).

The product of its digits is 746496, while the sum is 51.

The square root of 66918984 is about 8180.4024350884. The cubic root of 66918984 is about 405.9910373587.

It can be divided in two parts, 66 and 918984, that multiplied together give a square (60652944 = 7788²).

The spelling of 66918984 in words is "sixty-six million, nine hundred eighteen thousand, nine hundred eighty-four".