66906693 has 24 divisors (see below), whose sum is σ = 113438208. Its totient is φ = 37197792.

The previous prime is 66906647. The next prime is 66906703. The reversal of 66906693 is 39660966.

It is not a de Polignac number, because 66906693 - 2⁹ = 66906181 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66906613) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 12021 + ... + 16682.

It is an arithmetic number, because the mean of its divisors is an integer number (4726592).

Almost surely, 2^66906693 is an apocalyptic number.

66906693 is a gapful number since it is divisible by the number (63) formed by its first and last digit.

It is an amenable number.

66906693 is a deficient number, since it is larger than the sum of its proper divisors (46531515).

66906693 is a wasteful number, since it uses less digits than its factorization.

66906693 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28753 (or 28750 counting only the distinct ones).

The product of its (nonzero) digits is 314928, while the sum is 45.

The square root of 66906693 is about 8179.6511539307. The cubic root of 66906693 is about 405.9661797319.

The spelling of 66906693 in words is "sixty-six million, nine hundred six thousand, six hundred ninety-three".