66691005 has 8 divisors (see below), whose sum is σ = 106705632. Its totient is φ = 35568528.

The previous prime is 66691003. The next prime is 66691019. The reversal of 66691005 is 50019666.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 66691005 - 2¹ = 66691003 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66691003) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2223019 + ... + 2223048.

It is an arithmetic number, because the mean of its divisors is an integer number (13338204).

Almost surely, 2^66691005 is an apocalyptic number.

It is an amenable number.

66691005 is a deficient number, since it is larger than the sum of its proper divisors (40014627).

66691005 is a wasteful number, since it uses less digits than its factorization.

66691005 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4446075.

The product of its (nonzero) digits is 9720, while the sum is 33.

The square root of 66691005 is about 8166.4560857204. The cubic root of 66691005 is about 405.5294705879.

The spelling of 66691005 in words is "sixty-six million, six hundred ninety-one thousand, five".