66988551 has 32 divisors (see below), whose sum is σ = 111587328. Its totient is φ = 34859520.

The previous prime is 66988529. The next prime is 66988639. The reversal of 66988551 is 15588966.

It is not a de Polignac number, because 66988551 - 2⁶ = 66988487 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 66988551.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66988151) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 8041 + ... + 14093.

It is an arithmetic number, because the mean of its divisors is an integer number (3487104).

Almost surely, 2^66988551 is an apocalyptic number.

66988551 is a deficient number, since it is larger than the sum of its proper divisors (44598777).

66988551 is a wasteful number, since it uses less digits than its factorization.

66988551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6111.

The product of its digits is 518400, while the sum is 48.

The square root of 66988551 is about 8184.6533830090. The cubic root of 66988551 is about 406.1316740679.

The spelling of 66988551 in words is "sixty-six million, nine hundred eighty-eight thousand, five hundred fifty-one".