66666740 has 48 divisors (see below), whose sum is σ = 165172224. Its totient is φ = 22118400.

The previous prime is 66666731. The next prime is 66666749. The reversal of 66666740 is 4766666.

It is an interprime number because it is at equal distance from previous prime (66666731) and next prime (66666749).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66666749) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3341 + ... + 12020.

It is an arithmetic number, because the mean of its divisors is an integer number (3441088).

Almost surely, 2^66666740 is an apocalyptic number.

It is an amenable number.

66666740 is an abundant number, since it is smaller than the sum of its proper divisors (98505484).

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

66666740 is a wasteful number, since it uses less digits than its factorization.

66666740 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15408 (or 15406 counting only the distinct ones).

The product of its (nonzero) digits is 217728, while the sum is 41.

The square root of 66666740 is about 8164.9703000072. The cubic root of 66666740 is about 405.4802817142.

The spelling of 66666740 in words is "sixty-six million, six hundred sixty-six thousand, seven hundred forty".