66761440 has 48 divisors (see below), whose sum is σ = 166032720. Its totient is φ = 25297920.

The previous prime is 66761419. The next prime is 66761449. The reversal of 66761440 is 4416766.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 66761396 and 66761405.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66761449) 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, 7941 + ... + 14020.

It is an arithmetic number, because the mean of its divisors is an integer number (3459015).

Almost surely, 2^66761440 is an apocalyptic number.

It is an amenable number.

66761440 is an abundant number, since it is smaller than the sum of its proper divisors (99271280).

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

66761440 is a wasteful number, since it uses less digits than its factorization.

66761440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21995 (or 21987 counting only the distinct ones).

The product of its (nonzero) digits is 24192, while the sum is 34.

The square root of 66761440 is about 8170.7674058194. The cubic root of 66761440 is about 405.6721855787.

The spelling of 66761440 in words is "sixty-six million, seven hundred sixty-one thousand, four hundred forty".