66640260 has 48 divisors (see below), whose sum is σ = 193032000. Its totient is φ = 17157504.

The previous prime is 66640253. The next prime is 66640267. The reversal of 66640260 is 6204666.

It is an interprime number because it is at equal distance from previous prime (66640253) and next prime (66640267).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is not an unprimeable number, because it can be changed into a prime (66640267) 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, 17410 + ... + 20889.

It is an arithmetic number, because the mean of its divisors is an integer number (4021500).

Almost surely, 2^66640260 is an apocalyptic number.

66640260 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

66640260 is an abundant number, since it is smaller than the sum of its proper divisors (126391740).

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

66640260 is a wasteful number, since it uses less digits than its factorization.

66640260 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38340 (or 38338 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 30.

The square root of 66640260 is about 8163.3485776365. The cubic root of 66640260 is about 405.4265890745.

The spelling of 66640260 in words is "sixty-six million, six hundred forty thousand, two hundred sixty".