66799551 has 16 divisors (see below), whose sum is σ = 109620224. Its totient is φ = 35234784.

The previous prime is 66799547. The next prime is 66799559. The reversal of 66799551 is 15599766.

66799551 is nontrivially palindromic in base 4.

It is not a de Polignac number, because 66799551 - 2² = 66799547 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 66799551.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66799559) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 122071 + ... + 122616.

It is an arithmetic number, because the mean of its divisors is an integer number (6851264).

Almost surely, 2^66799551 is an apocalyptic number.

66799551 is a deficient number, since it is larger than the sum of its proper divisors (42820673).

66799551 is a wasteful number, since it uses less digits than its factorization.

66799551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 244710.

The product of its digits is 510300, while the sum is 48.

The square root of 66799551 is about 8173.0992285668. The cubic root of 66799551 is about 405.7493640203.

The spelling of 66799551 in words is "sixty-six million, seven hundred ninety-nine thousand, five hundred fifty-one".