66691480 has 16 divisors (see below), whose sum is σ = 150055920. Its totient is φ = 26676576.

The previous prime is 66691451. The next prime is 66691481. The reversal of 66691480 is 8419666.

It is a Harshad number since it is a multiple of its sum of digits (40), and also a Moran number because the ratio is a prime number: 1667287 = 66691480 / (6 + 6 + 6 + 9 + 1 + 4 + 8 + 0).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66691481) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 833604 + ... + 833683.

It is an arithmetic number, because the mean of its divisors is an integer number (9378495).

Almost surely, 2^66691480 is an apocalyptic number.

It is an amenable number.

66691480 is an abundant number, since it is smaller than the sum of its proper divisors (83364440).

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

66691480 is a wasteful number, since it uses less digits than its factorization.

66691480 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1667298 (or 1667294 counting only the distinct ones).

The product of its (nonzero) digits is 62208, while the sum is 40.

The square root of 66691480 is about 8166.4851680512. The cubic root of 66691480 is about 405.5304333667.

The spelling of 66691480 in words is "sixty-six million, six hundred ninety-one thousand, four hundred eighty".