66397680 has 60 divisors (see below), whose sum is σ = 222987960. Its totient is φ = 17705856.

The previous prime is 66397663. The next prime is 66397687. The reversal of 66397680 is 8679366.

66397680 is a `hidden beast` number, since 6 + 639 + 7 + 6 + 8 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (60).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66397687) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 45390 + ... + 46829.

It is an arithmetic number, because the mean of its divisors is an integer number (3716466).

Almost surely, 2^66397680 is an apocalyptic number.

66397680 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

66397680 is an abundant number, since it is smaller than the sum of its proper divisors (156590280).

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

66397680 is a wasteful number, since it uses less digits than its factorization.

66397680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 92238 (or 92229 counting only the distinct ones).

The product of its (nonzero) digits is 326592, while the sum is 45.

The square root of 66397680 is about 8148.4771583407. The cubic root of 66397680 is about 404.9340541918.

The spelling of 66397680 in words is "sixty-six million, three hundred ninety-seven thousand, six hundred eighty".