66420440 has 32 divisors (see below), whose sum is σ = 154602000. Its totient is φ = 25651584.

The previous prime is 66420421. The next prime is 66420449. The reversal of 66420440 is 4402466.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66420449) 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, 27470 + ... + 29789.

Almost surely, 2^66420440 is an apocalyptic number.

It is an amenable number.

66420440 is an abundant number, since it is smaller than the sum of its proper divisors (88181560).

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

66420440 is a wasteful number, since it uses less digits than its factorization.

66420440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 57299 (or 57295 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 26.

The square root of 66420440 is about 8149.8736186520. The cubic root of 66420440 is about 404.9803170844.

The spelling of 66420440 in words is "sixty-six million, four hundred twenty thousand, four hundred forty".