66997040 has 80 divisors (see below), whose sum is σ = 178917120. Its totient is φ = 23074560.

The previous prime is 66997033. The next prime is 66997061. The reversal of 66997040 is 4079966.

It is a tau number, because it is divible by the number of its divisors (80).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 14717 + ... + 18723.

It is an arithmetic number, because the mean of its divisors is an integer number (2236464).

Almost surely, 2^66997040 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 66997040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (89458560).

66997040 is an abundant number, since it is smaller than the sum of its proper divisors (111920080).

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

66997040 is a wasteful number, since it uses less digits than its factorization.

66997040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4050 (or 4044 counting only the distinct ones).

The product of its (nonzero) digits is 81648, while the sum is 41.

The square root of 66997040 is about 8185.1719590977. The cubic root of 66997040 is about 406.1488287712.

The spelling of 66997040 in words is "sixty-six million, nine hundred ninety-seven thousand, forty".