66890505 has 32 divisors (see below), whose sum is σ = 118972800. Its totient is φ = 31815680.

The previous prime is 66890503. The next prime is 66890513. The reversal of 66890505 is 50509866.

It is not a de Polignac number, because 66890505 - 2¹ = 66890503 is a prime.

It is not an unprimeable number, because it can be changed into a prime (66890503) 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, 4921 + ... + 12569.

It is an arithmetic number, because the mean of its divisors is an integer number (3717900).

Almost surely, 2^66890505 is an apocalyptic number.

It is an amenable number.

66890505 is a deficient number, since it is larger than the sum of its proper divisors (52082295).

66890505 is a wasteful number, since it uses less digits than its factorization.

66890505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7721.

The product of its (nonzero) digits is 64800, while the sum is 39.

The square root of 66890505 is about 8178.6615653174. The cubic root of 66890505 is about 405.9334360690.

The spelling of 66890505 in words is "sixty-six million, eight hundred ninety thousand, five hundred five".