66681340 has 24 divisors (see below), whose sum is σ = 152761392. Its totient is φ = 24247680.

The previous prime is 66681337. The next prime is 66681343. The reversal of 66681340 is 4318666.

It is an interprime number because it is at equal distance from previous prime (66681337) and next prime (66681343).

It is a super-2 number, since 2×66681340² = 8892802208391200, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 66681296 and 66681305.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66681343) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 151329 + ... + 151768.

It is an arithmetic number, because the mean of its divisors is an integer number (6365058).

Almost surely, 2^66681340 is an apocalyptic number.

It is an amenable number.

66681340 is an abundant number, since it is smaller than the sum of its proper divisors (86080052).

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

66681340 is a wasteful number, since it uses less digits than its factorization.

66681340 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 303117 (or 303115 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 34.

The square root of 66681340 is about 8165.8643143271. The cubic root of 66681340 is about 405.5098795817.

It can be divided in two parts, 6668 and 1340, that added together give a palindrome (8008).

The spelling of 66681340 in words is "sixty-six million, six hundred eighty-one thousand, three hundred forty".