66688554 has 8 divisors (see below), whose sum is σ = 133377120. Its totient is φ = 22229516.

The previous prime is 66688549. The next prime is 66688577. The reversal of 66688554 is 45588666.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

66688554 is an admirable number.

It is a super-2 number, since 2×66688554² = 8894726469221832, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5557374 + ... + 5557385.

It is an arithmetic number, because the mean of its divisors is an integer number (16672140).

Almost surely, 2^66688554 is an apocalyptic number.

66688554 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

66688554 is a wasteful number, since it uses less digits than its factorization.

66688554 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11114764.

The product of its digits is 1382400, while the sum is 48.

The square root of 66688554 is about 8166.3060192476. The cubic root of 66688554 is about 405.5245025771.

The spelling of 66688554 in words is "sixty-six million, six hundred eighty-eight thousand, five hundred fifty-four".