66994540 has 12 divisors (see below), whose sum is σ = 140688576. Its totient is φ = 26797808.

The previous prime is 66994537. The next prime is 66994541. The reversal of 66994540 is 4549966.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (66994541) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1674844 + ... + 1674883.

It is an arithmetic number, because the mean of its divisors is an integer number (11724048).

Almost surely, 2^66994540 is an apocalyptic number.

It is an amenable number.

66994540 is an abundant number, since it is smaller than the sum of its proper divisors (73694036).

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

66994540 is a wasteful number, since it uses less digits than its factorization.

66994540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3349736 (or 3349734 counting only the distinct ones).

The product of its (nonzero) digits is 233280, while the sum is 43.

The square root of 66994540 is about 8185.0192424942. The cubic root of 66994540 is about 406.1437768829.

The spelling of 66994540 in words is "sixty-six million, nine hundred ninety-four thousand, five hundred forty".