66635540 has 24 divisors (see below), whose sum is σ = 140213472. Its totient is φ = 26601120.

The previous prime is 66635501. The next prime is 66635549. The reversal of 66635540 is 4553666.

It is a self number, because there is not a number n which added to its sum of digits gives 66635540.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66635549) 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, 7895 + ... + 13985.

It is an arithmetic number, because the mean of its divisors is an integer number (5842228).

Almost surely, 2^66635540 is an apocalyptic number.

It is an amenable number.

66635540 is an abundant number, since it is smaller than the sum of its proper divisors (73577932).

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

66635540 is a wasteful number, since it uses less digits than its factorization.

66635540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6647 (or 6645 counting only the distinct ones).

The product of its (nonzero) digits is 64800, while the sum is 35.

The square root of 66635540 is about 8163.0594754663. The cubic root of 66635540 is about 405.4170169895.

The spelling of 66635540 in words is "sixty-six million, six hundred thirty-five thousand, five hundred forty".