66690749 has 16 divisors (see below), whose sum is σ = 70761600. Its totient is φ = 62763456.

The previous prime is 66690737. The next prime is 66690763. The reversal of 66690749 is 94709666.

It is a cyclic number.

It is not a de Polignac number, because 66690749 - 2⁴ = 66690733 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66690719) 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 15 ways as a sum of consecutive naturals, for example, 247787 + ... + 248055.

It is an arithmetic number, because the mean of its divisors is an integer number (4422600).

Almost surely, 2^66690749 is an apocalyptic number.

It is an amenable number.

66690749 is a deficient number, since it is larger than the sum of its proper divisors (4070851).

66690749 is a wasteful number, since it uses less digits than its factorization.

66690749 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 484.

The product of its (nonzero) digits is 489888, while the sum is 47.

The square root of 66690749 is about 8166.4404118318. The cubic root of 66690749 is about 405.5289516990.

The spelling of 66690749 in words is "sixty-six million, six hundred ninety thousand, seven hundred forty-nine".