66487680 has 384 divisors, whose sum is σ = 280687680. Its totient is φ = 14155776.

The previous prime is 66487643. The next prime is 66487693. The reversal of 66487680 is 8678466.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (384).

It is a super-2 number, since 2×66487680² = 8841223183564800, which contains 22 as substring.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 685392 + ... + 685488.

Almost surely, 2^66487680 is an apocalyptic number.

66487680 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66487680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (140343840).

66487680 is an abundant number, since it is smaller than the sum of its proper divisors (214200000).

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

66487680 is a wasteful number, since it uses less digits than its factorization.

66487680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 146 (or 131 counting only the distinct ones).

The product of its (nonzero) digits is 387072, while the sum is 45.

The square root of 66487680 is about 8153.9977924942. The cubic root of 66487680 is about 405.1169301146.

The spelling of 66487680 in words is "sixty-six million, four hundred eighty-seven thousand, six hundred eighty".