66507764 has 6 divisors (see below), whose sum is σ = 116388594. Its totient is φ = 33253880.

The previous prime is 66507761. The next prime is 66507769. The reversal of 66507764 is 46770566.

It can be written as a sum of positive squares in only one way, i.e., 66422500 + 85264 = 8150^2 + 292^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66507761) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8313467 + ... + 8313474.

It is an arithmetic number, because the mean of its divisors is an integer number (19398099).

Almost surely, 2^66507764 is an apocalyptic number.

It is an amenable number.

66507764 is a deficient number, since it is larger than the sum of its proper divisors (49880830).

66507764 is a wasteful number, since it uses less digits than its factorization.

66507764 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16626945 (or 16626943 counting only the distinct ones).

The product of its (nonzero) digits is 211680, while the sum is 41.

The square root of 66507764 is about 8155.2292426394. The cubic root of 66507764 is about 405.1577173667.

The spelling of 66507764 in words is "sixty-six million, five hundred seven thousand, seven hundred sixty-four".