66774987 has 24 divisors (see below), whose sum is σ = 102835200. Its totient is φ = 41631408.

The previous prime is 66774971. The next prime is 66774989. The reversal of 66774987 is 78947766.

It is not a de Polignac number, because 66774987 - 2⁴ = 66774971 is a prime.

It is not an unprimeable number, because it can be changed into a prime (66774989) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 11038 + ... + 15980.

It is an arithmetic number, because the mean of its divisors is an integer number (4284800).

Almost surely, 2^66774987 is an apocalyptic number.

66774987 is a deficient number, since it is larger than the sum of its proper divisors (36060213).

66774987 is a wasteful number, since it uses less digits than its factorization.

66774987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5047 (or 5044 counting only the distinct ones).

The product of its digits is 3556224, while the sum is 54.

The square root of 66774987 is about 8171.5963556700. The cubic root of 66774987 is about 405.6996229209.

It can be divided in two parts, 6677 and 4987, that added together give a square (11664 = 108²).

The spelling of 66774987 in words is "sixty-six million, seven hundred seventy-four thousand, nine hundred eighty-seven".